I recommend a few Blessed Bandages (Magic Item Compendium, page 152). Applying one immediately stabilizes a dying target.
As for your proposed solutions:
- Don't spend a feat on Spell Penetration. While Druids are usually not particularly feat-starved, Spell Penetration is a feat that benefits relatively few Druid spells and isn't all that powerful to begin with.
- Spending skill points on Heal is also a waste, you have more powerful skills. An exception might be if you expect to get a lot of utility out of the Healing Lorecall spell (Spell Compendium, page 110)
- Don't use potions. Save up for a wand instead. But yes, spells from items would still bounce off the Drow's SR, particularly if the Drow gains levels (improving their SR).
- Compared to other situations in which you might be willfully letting your friend's character die, this is a rather good one. The +2 Level Adjustment the character is carrying around means they are likely to be a liability (even with LA buyoff, it's going to stick around for a while). And yes, Drow are nasty creatures who are likely planning your demise already.
Yes, the wording does mean that a cleric of the Light Domain gains 'Fireball' as part of the Cleric Spell List; and here's why the wording is different. I hope the following helps explain why
"The following spells are added to the warlock spell list for you," which shows that Fiend patron warlocks have Fireball in their spell lists, and so should be able to use Spell Scrolls of fireball.
The above Warlock phrasing, just as it's phrased for Wizards and other spell casting classes that gain extra spells through means of specialization, is phrased that way because each of those classes have a spell list that they must choose spells from as they level up. They do not inherently know all spells available to a Warlock. So the phrasing in this case means the fireball spell is added to the list of spells he can POTENTIALLY add to his 'Spells Known' list. For intents and purposes, those are now on his Warlock Spell List
Now enter Cleric, and the Paladin; which have very different methods of spell learning.
If you have a domain spell that doesn't appear on the cleric spell list, the spell is nonetheless a cleric spell for you."
It must phrase it like this because Clerics and Paladins do not have to choose what spells they learn as they level. Clerics and Paladins inherently have the knowledge of every spell on their list....because we're awesome like that....and can prepare spells as needed in between long rests. If I wanted to go with cure wounds one day and then give up cure wounds to take Inflict Wounds after a long rest? I can do that freely. I have direct access to every spell available to Clerics. So when I choose Light Domain and it says the Fireball spell that isn't on my class list nonetheless becomes a cleric spell? It's now part of my knowledge of cleric spells (On my list of spells), and thus able to be utilized in scroll form since I now have the knowledge of how 'Fireball' works magically.
The only reason it doesn't say these spells are added to your spell list for you, is because it wouldn't matter in a Cleric or Paladin's case. Any spell that's on our spell list is a spell we can cast should we choose to. Any spell that's on a Warlock/Wizard/Sorcerer spell list, is a spell they can cast only if they chose it from their spell list when gaining levels.
Best Answer
Only the designers can accurately answer this; our answers would only be speculations.
It seems to me that each class's playtest spell list is made more distinct than in 3.x... by cutting spells from the list.
For example:
Bards no longer have Grease, Haste, Mirror Image, Blink, or other "mage-like" spells. Less support and buff, which renders them a lot more trick-oriented.
Clerics lost Divine Favor, Magic Weapon, Wall of Stone, Astral Projection, etc. Less fighting and controlling, and slightly more about protection and anti-undead/outsider.
Even Paladins and Rangers now see a very different and unique spell list (aura, smite, arrow spells).
Mages lost Detect Poison, Tongues (now Holy Accord), Daylight, and your example of Resistance. They are now slightly more focused on control (especially since they can only concentrate on one buff).
With the increased availability of healing/restorative spells (reducing diversity), and the introduction of sub-class spell list (further reducing diversity), I would say this is designed intentionally to keep the base classes more distinguished.
In fact, since cantrips can be cast at-will, they are the most used spells. Do you light a camp fire with Thaumaturgy, Fire Seeds, or Prestidigitation? Do you pray for divine Guidance before you do anything? Perhaps you Ray of Frost all your drinks. In real play, they really say a lot about your class.
Or you can work out an abjuration mage with your DM, with the Resistance cantrip as a class feature.