I'm only in the first town - just did the 'rustle the brahmin' quest, which obviously prevents me from doing the 'protect the brahmin' quest.

Upon looking in my pip-boy status, the 'protect' quest is still listed (rather than being removed, or crossed out as a completed quest would be)

This really irks the OCD completist streak in me... I'm guessing this is a normal fallout 'feature' and there's nothing I can do about it?

Well, I've been scouring the web and can't find any answers on it. In the end I started a new game since it bugged me that much. Damn OCD.

Now those thieving kids in the Den are driving me nuts. Little blighters.

If it's any comfort, you weren't the only one doing a little scouring.
This would be more comforting, I imagine, if I actually had better results than you did. I didn't.

It's a pretty bizarre oversight in the game - I wonder if a patch could be made to correct such issues? No doubt it's encompassed in one of the larger multifunction patches, but I'm not keen on messing with the game that much.

Those bloody children stole a quest item off me and sold it to a vendor, took ages for me to track it down. Needless to say, that vendor is now TOAST.

Heh.

*snickers* But now if they steal something that important, you can't get it back...

...you'll have to kill the children, too.
I recommend explosives.

You can steal directly from the kids in full view of everyone, without any negative karma or other aggro. Thank god.

I can't comment on the permanently unfinished quests (I didn't even know the one with the cattle was one), but regarding the stealing children, here's a tip...
When they steal something, they immediately bring it to one of the two traders. If you notice they stole something from you, run ahead of them and lock the corresponding trader's door using the lockpick skill. That way, you can try stealing back your stuff as many times as you wish. Then, you can just unlock the door.

If you don't want to worry with the thieves, start combat, enter in building, close combat. ^^

Have you tried seeing if he attempts it when you try to Repair something?
I find the number keys are great for triggering the skills. They're in order, so 5 is First Aid, 6 Doctor, 7 Repair, stuff like that.

^What MackieStingray said - when you attempt something which is a skill of a party member, said party member will try to do it instead of you (unfortunately, even if they are actually less likely to succeed).
Back on topic of permanently unfinished quests: I don't know if it can become one (I've never tried to do them at the same time, I don't know if that's even possible, but I thought it merits a warning), but when you get to Broken Hills, watch out for two certain groups who have very... serious disputes. I *think* it has the potential to cause a quest or two to be unfinished, but, like I've said, I'm not sure.

+Ratings for everyone that provided info in this thread - thanks guys, I've learned so much here :)

I had no idea about:

* Locking doors
* Companions auto-using skills
* Numpad shortcuts for skills
* Being thief-proof 'in combat'

Sucks that there's no way to 'wipe out' unfinishable quests - guess that's one of the ways FO3 improves the formula :)

More questions:

*Can NPCs Unlock doors that you've Locked? And if so, how do the mechanics for this work? Do they have to challenge your lockpick skill, or does each door have it's own difficulty rating?

* Is there a way to over-ride NPCs trying to help you with their inferior skills?

I think I'm gonna have to learn to live with the unfinished quest thing. Already restarted my game twice and I'm not keen to do it again, lol. I envy those of you who don't feel the compulsion to see those quests crossed out!

NPCs don't try to unlock doors on their own, or at least not that I know of (as in, I've never seen it happen).

Only if you make them leave the group (you may have to do so in an other area, but I'm not sure about that).