I say 'thank you' a lot too. Or describe the thing I like rather than "Good boy" - so "That's really kind, to share" or "That's really helpful, DS, thank you" or for the generic well done/clever boy I say things like "You did it all by yourself" or "We did it together!" or "You built a tower Oh wow, it's very tall."
I don't think anyone I know would be offended by a thank you - so probably cultural. could you say something else like "I really appreciate you helping me tidy" or something.
Some points a bit further back - it seems there have been lots of newcomers so it's moved fast. Sorry if anyone feels missed out - feel free to just ask again if your question has been lost in all the new responses :)
Nappyaddict, DS still isn't allowed to walk by busy roads unless the pavement is very wide, and he's 2.7. I can't remember when he started walking by medium roads - possibly around 2ish. He didn't walk unaided until sixteen months so it was a while before he could walk that far anyway. But he's never liked holding hands either. He's got better at it recently.
With saying no even if you know it will upset them, I find a delayed no can help. So not no you can't have ice cream, but yes, you can have ice cream tomorrow. Or offer an alternative. Would you like a yoghurt? And try to keep the actual nos to a minimum. I find actually that DS is usually distraught for a minute or two but then he's absolutely fine, so now I know he's just expressing his initial frustration and upset it's easier for me to cope with. If you imagine the feeling when you go to a shop to get a specific thing and they are sold out, then you can imagine how they are feeling, and then just multiply that by you've just had a bad day, you're tired and you have PMT. It helps me sympathise with toddlers anyway. 
Booty - him climbing down might not have to be unsafe, perhaps? could you for example remove the tray and then stand there holding the highchair in case it tips, so that he's allowed to climb out himself but only in specific circumstances. I'm not sure patience would be a concept he could understand really if he's still young enough for a highchair. But yes I think reinforcing what you want him to do is a good thing. What about trying to think of a word you might use - I wouldn't say to DS "be patient" but I might say "You need to wait" - so how about "Thanks for waiting, shall I help you down now?"