Aloha! I can only tell you how I was with my own son. He's 17 now, so I guess I can say with some certainty that SOMETHING I did was right! (I say "I" because my husband pretty much just let me do my own thing with him!) He's an incredibly mature, well-balanced, kind and intelligent individual. He's never gone through that "I-hate-my-parents" stage and was never embarrassed of us or my hugs and kisses. He's a great student. OK, so enough about my "credentials"!
I always listened to him and took time for him (in this, I was lucky because I was able to work only part-time). I slowed my life down to match his. I think, looking back, that I figured he was kind of like I would be if I were to land tomorrow in a foreign country. So I took time to explain things to him in a way I thought he could relate to. If we went into a toy store but I wasn't planning on getting him anything, I'd explain ahead of time that we were just going in "to check out the possibilities." I explained that all those things belonged to the store until we exchanged money for them. (We even talked about how people used to exchange work for food or items for items, etc., but that now we use money instead and isn't that interesting?)
If he really wanted something, I'd suggest that we remember exactly what it is and, as soon as we get home, let's write it on our Christmas (or birthday) list, which was always at his level on the refrigerator. If it was something it seemed he REALLY couldn't live without, we'd talk about it and, if it wasn't too huge (a swing set, for example!), I'd just get it for him. I mean, haven't we all had those "I-can't-live-without-it" moments? I know I have!
So, if he's afraid to climb, go with that. He'll climb when he's ready. Maybe that'll be in a week, maybe it'll be in a year or two. My little guy wouldn't even attempt something until he knew he could do it. And then when he did, he would master it on the first try! As for the other toddlers, don't worry. We all have different skills (your son probably has some that they don't), we all grow in different ways and at different speeds. And maybe he's just not the sporty kind. Would you be OK with that? I mean, what are you telling him by trying to force him or pointing out to him that the other kids are doing it? That he's not good enough, that you don't like this about him. I always asked myself: Am I doing/saying this for HIM or for ME?
Same with the potty training. He'll do it when he's ready. Unless you HAVE to have him trained by a certain date, for some reason (like preschool or something), I'd just leave him. I've never met a 7-year-old in diapers (I know some kids have problems at night, but that's a different story). You might have to give him a little more time now, because of the earlier experience.
The tickling thing, I don't know. It's certainly not going to resolve anything, but it sounds like it helps distract both of you. It's kind of like changing the subject. The issue's still there, you're just not talking about it. Whatever works, is my motto, I'd just remember to get back to whatever the issue was a little later, when things have calmed down and you can listen to his side and present yours.
When we talked about things, I tried to present things in terms of experiences I knew he'd had before, with friends, at school, etc., like: Remember how you felt when ...? Or remember how you were worried about ... and it all turned out OK?
We did a lot of compromising, the way you do with other adults. After all, when was the last time you said a flat-out NO to an adult without even explaining? Why would you treat a child with any less respect?
Anyway, this is long-winded and I guess it all comes down to the last thing I mentioned: respect. And with that comes trust. Trust that if you let him, he'll be OK. If you respect him, he'll learn to respect himself and others.
Hope this helps a little. Good luck! Two is a great age (so is 3 and 4 and 5 and 10 and 17 ...!)
K.