Corpsecrafter et al. each apply to “undead you raise or create with any necromancy spell.” The Ritual of Crucimigration does not involve any spellcasting, only cursed nails, chanting, and the invocation of “evil powers and gods.” It is these things, rather than the ritual leader him- or herself, that result in the creation of the necropolitan. The ritual leader is just ensuring the proper timing of everything. Therefore, the feats that the ritual leader does or does not have do not apply, and again, since no spell was cast, Corpsecraft et al. wouldn’t anyway.
This was likely written this way specifically to avoid players easily getting substantial benefits at no cost to themselves.
On the other hand, desecrate does not have any such provisions. This implies that a necropolitan could gain the +1 or +2 HP/HD that desecrate offers to every “undead creature created within or summoned into such an area.” However, there is no indication that this is a permanent bonus: it is an effect of the spell. Once the spell expires, or the necropolitan leaves the area, the benefit is lost.
Necropolitan is a fairly high-power template. The benefits of the undead type are considerable. The costs are fairly considerable as well, but it is well worth considering for many characters, and dread necromancers benefit particularly well from it. That’s all fine, but piling extra bonuses on top, such as Corpsecrafter or desecrate, that cost you nothing, as they are aspects of whoever performs the ritual, that pushes the template beyond what I would consider acceptable. If I allowed a player to use these, I’d feel the need to offer ways to empower the other characters as well.
Which, of course, can be done and can be quite fun, but it’s definitely not an automatic part of necropolitan.
Immunity or Resistance can only be suppressed if the text specifically mentions it.
Here is an example of an immunity:
Cold Immunity: A creature with cold immunity never takes cold damage.
As you can see above, there is absolutely no mention that you can suddenly not be immune to cold whenever you feel like it.
Here is an example of resistance:
Spell Resistance: Spell resistance is the extraordinary ability to avoid being affected by spells. A creature can voluntarily lower its spell resistance.
As you can see above, there is specific mention that you can lower your resistance; you probably wouldn't want to resist a restorative spell being sent your way - unless you wanted to.
Regarding an Undead Dread Necromancer specifically...
First, lets look at the ability in question:
Charnel Touch (Su): This touch heals undead creatures...
Negative Energy Resistance: A dread necromancer gains a bonus on saving throws made to resist negative energy effects...
Now, lets look at the Necropolitan template in question:
Size/Type: The creature's type changes to undead...
As mentioned in previous answers, there is no saving throw to apply the resistance to. The Charnel Touch would heal the Necropolitan, since the Necropolitan is an undead creature - there is no saving throw - it just happens.
Now, regarding the Undead's:
- Immunity to all mind-affecting effects (charms, compulsions,
phantasms, patterns, and morale effects).
This is overcome by one feat, that the bard should have taken knowing there was an undead presence in the party (and on his/her side):
Requiem (Libris Mortis, p. 29): You can extend the effects of your mind-affecting bardic music abilities so that they influence the undead.
Before someone asks, "Is Inspire Courage a Bardic Music Effect?"
Yes, it is. See below:
Bardic Music states: "While these abilities fall under the category of bardic music... they can all be activated by reciting poetry, singing lyrical songs... Each ability requires both a minimum bard level and a minimum number of ranks in the Perform skill..."
Inspire Courage requires 3 or more ranks in a Perform skill, and uses song or poetry.
Best Answer
Technically, a proper burst can't usually be centered on the creature that created the burst...
When a spell or effect affects an area that's a burst
Emphasis mine. So when a creature casts, for example, the 2nd-level Clr spell sound burst [evoc] (PH 281) with its area of a 10-ft. radius spread or the 8th-level Sor/Wiz spell sunburst [evoc] (PH 289) with its area of an 80-ft. radius burst, the crosshairs at which the area begins can be adjacent to the caster, but the point at which the area begins can't be a square the caster occupies. (Many games such as GURPS and the Hero System—even some d20 games like either edition of Spycraft—do count actual hexes or squares instead of counting crosshairs to crosshairs when dealing with burst-like area, so Dungeons and Dragons 3.5 is exceptional in this case.)
...But everything described as or named a burst isn't, technically, a burst
Sometimes names and descriptions of effects in Dungeons and Dragons demonstrate a shocking lack of imagination. Lots of things that are called bursts don't conform to the technical definition of a burst. Seriously, the 1st-level psionic power burst [psychoportation] (XPH 81-2), for example, isn't a burst at all! And the 0-level Sor/Wiz spell flare [evoc] (PH 232) says Effect: Burst of light, yet that burst of light affects but a lone creature.
The dread necromancer's supernatural ability negative energy burst is one of these fancifully named bursts—not a technical burst—, its specific description overriding the general rules of bursts with its details describing exactly how it functions:
This effect affects creatures in and adjacent to the dread necromancer's space but doesn't affect the dread necromancer himself because he's emitting the effect. Would it be easier to adjudicate were it phrased like the 9th-level Sor/Wiz spell wail of the banshee [necro] (PH 298)? Sure, and such a description would also make it clear how the special ability charnel burst interacts with obstacles, yet negative energy burst's phrasing is clear and playable enough.
(Note that the special ability negative energy burst is hardly unique in being a burst centered on the burst's creator, especially taking into account psionic powers. For example, the 3rd-level psion/wilder power energy burst [psychokinesis] (XPH 101) is a burst centered on the manifester yet dealing no damage to the manifester, while the 6th-level psion/wilder power breath of the black dragon (XPH 81) is a cone-shaped burst centered on the manifester without such an exception! It would've been kind of the developers to've included rules for adjudicating such effects, however. In particular, emanations—especially the effect created by the 6th-level Sor/Wiz spell antimagic field [abjur] (PH 200)—would've benefited greatly from only a few more words of explanation and a diagram.)
In sum, a dread necromancer's negative energy burst does not affect the dread necromancer...
Thus, while it is possible to catch oneself in the area of one's own burst—like in a fireball spell's Area: 20-ft.-radius spread (which, by the way, has been happening for literal decades) or whatever—, it's not possible for a dread necromancer to catch himself in the area of his own negative energy burst. Your player's tomb-tainted dread necromancer is unaffected by his own special ability negative energy burst, but, if it's any consolation, he can still touch himself as a standard action to benefit from his supernatural ability charnel touch.
...But a house rule saying that it can is totally okay
Even if a house rule allows the tomb-tainted dread necromancer to take a standard action 1/day (+1 time/day at levels 8, 13, and 18) to use the supernatural ability negative energy burst to deal 1d4 points of negative energy damage/level to creatures adjacent to his space and to himself, game balance won't be upset. Taking a standard action to heal a comparatively minor amount of damage to himself and some minions (while possibly endangering his living allies) when that standard action could've been spent casting spells that kill people? That's a choice a dread necromancer can be allowed to make without fear of him dominating the game.