You seem to underestimate how annoying the life from a thief is, we tend to fail stealing a single cap with even 300% steal, and really, we spawn at Klamath more often than you think. these days no one carries good items in NCR anyway we barely make any profit, and get shot often. and there is the problem that it takes ages to actually level your thief character.
My experience exactly.
I've been leveling my thief character for about 2 months now (no exploiting, so it takes long) and am a few 1000 xp away from level 21.
It's hard, but I have to say it was the build that was the most fun to level.
Thieving at vendors places should be considered the same as blocking, because it makes vendors inaccessible (if you dont want to lose your stuff), and in real situation, no shop owner will let the thief steal in his shop...
Vendors are perfectly accessible.
I have no problem trading, even when thieves are around, although sometime it takes longer as you have to run off from time to time.
The only thing that needs to be dealt with here are the thieves who keep harassing the same player, trying to steal from them over and over and following them around.
Oh wow...
"we tend to fail stealing a single cap with even 300% steal,"
And yet you often easily steal rifles and heavy ore from peoples' back pockets in plain view of 3 guards and a shop keeper. And what do you lose when you fail a steal attempt? Oh that's right:
"we spawn at Klamath more often than you think. these days no one carries good items in NCR anyway we barely make any profit, and get shot often."
You get shot and lose nothing.. then from klamath its 5-10 minutes to get back to NCR.. less if you just kill yourself until you respawn closer. And you barely make a profit? Define profit please, because thieves don't really cost you anything you should be making 100% profit.
" and there is the problem that it takes ages to actually level your thief character."
So guards, shopkeepers and players should respect your efforts by letting you walk around town stealing in front of everybody and going unpunished?
Read the last bit of my original post again.
"Stop nerfing stealing, it's hard enough now."
I'm suggesting punishments for getting caught being an ass in town (not just stealing) and a way for people to defend themselves from prolific and careless thieves. I'm not suggesting the steal skill be nerfed.
Being a thief is rather unprofitable when you look at profit and the time needed to get it.
As long as thieves don't bother guards and shop keepers, they indeed should leave them alone.
Most likely thieves are also their biggest regulars when it comes to trading.
You're suggesting thieving gets nerved, implying the steal skill gets nerved.
It's hard the way it is, try for yourself to find out.
Which is what I did.
Right now thievery don't seem to have any other meaning than give very limited source of excitement to its player. Because of severe consequences from getting caught steal >200 is recommended and with that you can't do anything else but steal. You can't use the weapons you steal, you can't craft, you can't fight. The whole thief-class is unfinished, it doesn't even have a real place in the game world. It would be all the same if the whole skill just ceased from existing.
Before you start wondering should using steal skill be easier or harder you should think about what's the point of stealing in first place.
If I remember correctly from my thief build, around 180% in stealing makes you quite good, over 220 it's really good.
I'm over 250 now with my build and don't see much changes with around 220.
Thief builds are a way to support your faction with items and caps to get a base, buy equipment and resources, mercs, etc.
It's a very useful and fun way to do so.
The point of stealing is to get stuff and caps and to have fun.
Only real problem with stealing is the whining of the victims.
Not suggesting you are, but in my experience the biggest whiners are other thieves, pk's and people acting like assholes.
Descent people only seem to warn others for thieves and shoot them when they're unprotected.
Off course there are exceptions.
I think the problem here is the similar like in other skills. Players push their characters up to 300% and don't have much points left for other skills, which leads to a "thief powerbuild", you cant do anything other then stealing. Cap the skill limit at 200% at maximum. Then, there'd be a few points left, to invest in some basic gun skills etc. Otherwise, everyone pulling every single skillpoint into one none- combat skill and then whining that levelling is too hard/thiefes only can do one thing proper... 
Well.
It will only lead to a different powerbuild, the "sneaking thief" which still can do not much more than stealing.
Personally I love how hard it is to level a thief with no combat skill.
Mine leveled pretty nicely due to some points in FA (which is a nice skill to combine with FA as people might have seen you heal others
).
As I said somewhere earlier in this reply, the only thing that needs to be dealt with is thieves harassing the same player over and over till they leave the map or till the thief gets killed.
Some kind of increased cooldown timer for thieves who steal from the same player 3 times or more in a row needs to be implemented.
To make it easy, no difference between npc and pc in this case.
I'm open for any other suggestion that stops thieves from following players all over the map, even though they know the player is on to them.
