I always perk out Speech, but I tend not to bother with the Lockpick +gold perk because I can sell smithed items for far more than that. I do buy and fully decorate all the houses, although I tend to pick one to use as a base of operations and store everything there rather than spreading it out between them.
Even though I do that, and do it as early as possible, combat is still easy. Then again I usually play sneaky archers of various kinds, so a lot of fights end without my ever being spotted, let alone attacked in return. Honestly, though, combat in TES games has
always been fairly easy, with the possible exception of low-skill combat in
Morrowind due to poor to-hit mechanics, since the AI is as dumb as a fence post and about as perceptive to boot.
That said, actors in
Skyrim will at least check the immediate vicinity of a stealth kill for the perpetrator, and if your sneak is low or you get sloppy they can actually find you. If enough of them find you and you don't yet have top-end gear they can actually kill you; it tends to be a little
too easy to split a group up and snipe them down one by one, though, so ending up in such a scenario is rather more rare than it really should be.