#3 - Players typically purchase their starting gear from the gold they are given at first level. The SRD has a great article on character creation, and equipment is under section 8. The gold you have listed is, according to the SRD, actually the average for each class. As a DM, you can choose to give them the average for first level, or make them roll.

It would be good for them to look at the pre-bought sets the describe, so they can understand what's typically needed. Once they get more comfortable, they may branch out according to how they like to play their character.

Of course, as the DM you may overrule this and force them to start with a certain set of items, or give them more gold, etc. Seeing as this is your first time playing, however, I highly suggest sticking to rules as written since this sort of overruling may very well have unintended side effects.

As an aside, wizards get so little at first level because they don't need (and cannot wear) armor, nor do they need expensive weapons like swords and bows.

It sounds like the foe is always going to succeed on all his saving throws. That means developing another method of

Getting a Target to Fail a Willpower Saving Throw

• The ioun stone (flawed mulberry pentacle) (8,700 gp; 0 lbs.) causes its possessor to take a -2 penalty to Willpower saving throws. According to the glossary penalties

  are numerical values that are subtracted from a check or statistical score. Penalties do not have a type and most penalties stack with one another.

  In other words, ask the DM if the penalties from multiple mulberry pentacles stack (maybe couched as, "Were my character to have several of these spinning around his head, would he suffer the penalty multiple times?" if the DM-player relationship is particularly adversarial--see below). Then determine if creatures can be involuntary possessors of ioun stones: "When a character first acquires a[n ioun] stone, she must hold it and then release it, whereupon it takes up a circling orbit 1d3 feet from her head," says the description, but later the text says that ioun "stones only float when sent spinning around the head of an intelligent (Int 3+) creature." Emphasis mine. Experiment on the cohort. If penalties stack and involuntary possession is possible, the spell invisibility [illus] can affect objects; a level 17 alchemist should be able to manufacture such ioun stones and render them invisible, while a level 20 ninja may be able to succeed on a sufficiently high enough Sleight of Hand skill check to send spinning around a sword saint's head a handful of invisible mulberry pentacles without the victim noticing.

• The spell limited wish [univ] causes the target to suffer a -7 penalty to his next saving throw, and the spell wish [univ] can force the target to reroll a successful saving throw via undoing misfortune. (Hey, it was a misfortune... for the ninja.)

That's all I have that don't also require another saving throw or conspirator (like MrLemon's witch). If the first method doesn't work, the ninja's still facing a level 20 character who likely has multiple methods of rerolling his saving throws (e.g. a golf bag full of luck blades). Thus, even with a limited wish and a wish involved, success is far from guaranteed.

That's because failing a saving throw ends characters' careers. It should be difficult--if not impossible--to make a character fail a saving throw outright by any means. We readers--at this point in the question's evolution--don't know what spell the cohort's casting from that scroll, but a failed saving throw could lead to the success of spells like dominate monster [ench], imprisonment [abjur], magic jar [necro], or trap the soul [conj]. Neither the DM nor you want those kinds of effects possible sans a saving throw, or even with a saving throw yet obscenely reduced.

The Foe's Probably Invulnerable Anyway

I'm speculating here, but if the DM's already told you the foe always acts in the surprise round, is never flat-footed, and can't be flanked, then--while that combination of abilities is possible--it sounds like the DM's subtly telling you No, and he wants you to find the foe's Secret Hidden Weakness^TM instead of confronting the foe directly. That shouldn't stop your attempts to confront the foe directly, but expect such confrontations--no matter how convoluted your plan--to fail until your ninja's found the MacGuffin or mastered the secret technique or whatever. It might be worthwhile questing for that rather than a method to make the foe fail a saving throw.