It is not like your reputation just dives in the depths of hell. No. But, game works that way that if you stole something in the city, earlier or later town guards would start to seek for the thief, and they would constantly stop you for searching. Sure, noone saw you, and stolen stuff long ago stopped being “hot” so you can even sell it to common trader, but, well, that is how game works. A minor annoyance, nothing more - if you weren’t carrying a lot of stolen stuff right at the moment, guard called you to stop. (Funny story here: as I couldn’t find trousers, I wanted, I stole them from the monk near Uzhitz, whom I knocked out, repaired said trousers and started to wear. Then I pay a visit to Rattau, and after some shopping get stopped by the guard for the search. But I have stolen trousers right in my inventory, so I have to take them off and throw out. Must have been a sight…)
Lockpicking… Well, you’ll get used to it. It is still better than in Oblivion, and leaves some challenge in comparison with Skyrim/Fallout mechanic. Just for you to know - at the start there was no signs to understand position of lockpick, related to rotating lock, they were added to UI later. Right now lockpicking feels, well, easy, when you get used, and that is just how I like things to be.
Welcome to the Kingdom Come - you may make things work in different ways here. Well, when such opportunity was added by the devs. Despite all gamedesign and technical problems, I praise that game exactly for this - variety of ways to play.