piranha1: About making a cleric with single level of paladin (for weapon skills, Charisma-boosted saving throws, etc.), if say, I start as paladin and then go cleric, or pick paladin level as my second one, and then in the future lose my Lawful Good alignment, what'd happen, would paladin-ish feats etc. stop working, or would I just be unable to gain more paladin levels?
The latter.
I only know of one or two mods that implement a true fallen paladin system, and in one of those it's a plot point.
Indeed, some people like to make multi-class paladin/blackguards to get double their CHA bonus to saves.
piranha1: Also is there any reason to take Still Spell (
http://nwn.wikia.com/wiki/Still_spell ) feat as a cleric? The way I understood the description, it only does anything for arcane spellcasters, so is actually useless for a cleric?
It's not terribly useful for a cleric, no. The only function is spellbook management: with Still Spell, you can memorise spells in a higher level slot if you want to. For example, Clerics have tons of great level 6 spells, but not that many great level 7 spells. So you could use Still Spell to memorise more Heal and Harm spells.
However, Silent Spell does just as good a job for that, and at least provides some very marginal benefits. And Extend Spell is much more useful and can also help spellbook management, although it won't work on all spells. You can't extend Heal, for example. But you can make do by extending Blade Barrier and True Seeing instead. But that won't help if you want to, say, memorise 10 Undead to Death spells when you go exploring a tomb. For that, you'll need Silent or Still.
piranha1: Also, stats: with Divine Power spell setting the Strength to 18, is there a reason to put any points above 10 in Strength? (well, carrying capacity I guess, but other than that? as a cleric, I might take a warrior-type henchman with me, and have them carry the stuff I won't be able to, and maybe also buy the bags of holding later)
No, clerics absolutely need a high STR score.
Carrying capacity alone would be enough reason to get more strength. Full plate isn't light, and with low DEX you'll need that. (since you need STR, CON and WIS, and CHA and INT don't hurt either, so DEX is the only stat you can safely ignore.)
Secondly, you won't have Divine Power for quite some time, and even then it won't be up all that time since it lasts a fairly short time. (Unless perhaps you're epic level and have memorised a ton of extended versions.) So you'll need more STR for the less-critical fights, as well as the early game.
Thirdly and much more importantly, the spell only accounts for modified strength, not base strength. So if you have other spells or items that boost your strength, the STR boost from divine power isn't going to work anyway. Bull's Strength, a 2nd level spell, boosts STR up to 5 points, or 7 empowered, and last 20 times as long as Divine Power. Belt's of Giant Strength or Gauntlets of Ogre Power bolster it even further. This means that by the time you get the spell, you're unlikely to get much benefit from the STR boosting component already, since you'll have some magic items by that point.
You could, of course, unequip your STR boosting items, then cast divine power, and then re-equip them. That would net you some benefit. But it's a pain in the arse, really. And it doesn't work for spells like Bull's Strength.
Fourthly and most importantly at high levels, the STR boost provided by the spell counts towards the +12 cap on stat boosts. So if you have a strength of 10, you'll never get more than STR 22, even with all the best items and the divine power spell. A base STR of 18, meanwhile, would net you a modified STR of 30 with spells like Bull's Strength and some magic items active. This makes a huge difference at higher levels.
In other words: clerics need STR. If you want your cleric to focus on fighting, you need it more than WIS, as long as you have the 19 base WIS you need to cast the highest level spells. Never neglect strength.
