Richterm's Retreat Nordock

I'd use this as a reference for the UMD question:

http://nwn.wikia.com/wiki/Use_magic_device

The thing to keep in mind is that except for that first class emulation point, the next level of success comes in multiples of 5. So taking an off multiple of points in UMD doesn't really help you, unless you can boost your charisma in some fashion to likewise boost your UMD (spells, potions, items) to the next multiple of 5. I don't recall seeing any items in Nordock that boost the UMD skill directly (only indirectly through charisma).

If you are looking to make a master of all these skills, technically, you can't get more than 43 base in any of them (level + 3, if not a cross class skill), along with skill focus (+3) and epic skill focus (+10), so you'd be looking at a max of 56 in these skills, then with any adjustment you get from ability bonuses and item bonuses in game that apply to the particular skill. There's also a max of +50 to skills (form items, spells, and effects) but I don't know if it applies to the skill focus feats - it might. There are a few items that boost open lock and disarm trap skills, but it might be better to wear bracers of dexterity +5 vs gloves of the rogue for example.

Anyway, if you did max them all out, you would be quite able to handle the vast majority of things in Nordock. Whether you'd need to max them all out is unlikely.

Opening a lock or disarming a trap can be affected by whether or not you are in combat - they get a +20 to the DC check roll if you aren't in combat, or if you have the Skill Mastery feat (rogue only, and would need at least 10 levels of rogue to get it - it's a rogue bonus feat so can only be taken by a rogue on a rogue bonus feat level, the first being 10). On Nordock, there is a special tool for opening locks and disarming traps... you'd need to use this tool on the vast majority of things, though there are a few low level traps that you can use the standard NWN radial menu to disarm. Locks and traps over a 35 DC can only be opened by a character with rogue levels I believe - one rogue level would do, though you'd want to have a decent amount of skill points to get to the DC level (including the +20 if not in combat, or with Skill Mastery).

Just some basic thoughts on the overall question, I don't have a hard number to give you to tell you when you've gotten enough skills in any to always be successful.

To be as close to accurate as I know, pretty much almost every lock/trap can be handled by 1 point in their relative skills and keeping ahold of the items that bump those skills up a little (like Gloves of the Rogue). Going to 5 or 10 most certainly would make things a lot smoother for some, but if you don't mind retrying, you should still be able to pop open things.

It's important to note though, that most of your items will come from random enemy drops, rather than chests. Most of the time, even if you loot every chest on the server in a reset, you won't get anything special (though occasionally, you will).

Using a level 9 scroll requires a UMD DC of 34 to be met. 30 will use pretty much everything (I think) although one or two items with alignment specific restrictions might go to 35.

There are some chests with unusual items, or even unique items, given a certain set of circumstances. If the same greedy character rushes around looting these chests at each reset, however, they will only get random treasure.

I can't answer the lock DC, but there are some traps with very high DC, also some traps which are not disarmable.

Yes, there are chests which can spawn items not normally found in loot tables, but it's *very* rare for even one to load something and for the largest part, most of those unusual items just are not that useful other than 1 or 2 of them, so worrying about chests as opposed to just building a solid farming character and hitting high-level areas is not a wise trade-off in terms of hunting for items, imo. I wish it were, but being able to efficiently kill 100 GNF bandits or Unseelie Sidhe Lords will net you far more useful treasures than 100 chest pops.

*cough* Roleplay server *cough*