Aw BAJ, I understand where you're coming from (as far as hating to be the first one to make a move, or reading something into people not responding), but more often than not it's got nothing to do with you if they don't respond. They're own life may have taken over temporarily, they may want to do a good job of writing you properly, they may themselves be afraid of rejection and think you are mocking them if you act complimentary or friendly or have some other kind of defenses up, they may just be bad correspondents. They may feel embarrassed for the long delay before responding and conclude that it is too late. Anyway, give them more than one chance at you!
I found that this place was a great spot to experiment with approaching people first, because the stakes were low. I was astounded by how much more warmly people responded to me when I just assumed they'd be friendly and initiated contact. This site has also helped to teach me more than once that when people respond in a prickly way, it is not really my fault or responsibility and not to take it terribly personally.
It took me until my early thirties though to finally understand why people responded well to those around me who weren't even terribly loyal friends (they reached out first and assumed friendship rather than waiting for confirmation of it before approaching), or why a lot of people didn't really know much beyond their surface perception of me (I didn't volunteer much until I knew they were interested in being friends). Once I started approaching people more, I found that there were some people who had actually been AFRAID of approaching me (which seemed unfathomable, as I thought I was the one that felt like a schmuck, not them!) whose friendship I had been missing and I was also surprised at how much friendlier people seemed to be generally.
I still don't have it all cased or anything, but I think even understanding that to be true intellectually and working on expanding my comfort level has helped me considerably.