Wouldn't the transaction fees only be for vendors/exchanges and not effectively affect the amount of actual bitcoins in circulation?

i've been following this whole bitcoin thing for a while now and i finally caved in. i own 1.5 BTC now and have already lost money. regardless, i live in new york city and have a decent job so i am by no means claiming to be "poor" (still living paycheck to paycheck but it's worth it)

i had a couple questions

1) is blockchain only a "wallet site"? or can i buy/sell bitcoins on there. i keep trying to click the "markets" tab but it doesn't take me anywhere.

2) for those who do use blockchain, how would i go about transferring my bitcoin (and a half) to an exchange such as mt. gox - because so far it doesn't seem like i can even do that.

3) how useful are these asic bitcoin miners? i want to preorder one because i have a powerful computer but i feel like buying an external miner would be helpful. i've done my fair share of research with hashing and feel like a miner would be a decent investment.


disclaimer: i really do like the idea of bitcoin - i am by no means an engineer or programmer but as mentioned, i want to become part of the bitcoin movement and wanna get to know a little bit more before i go ahead with depositing more money and investing in a miner.

for those who are super high rollers in the bitcoin game, i would appreciate any donation (i know how pissed you people get about these things, sorry) so i can start building an efficient mining machine and hopefully move from a newbie to an actively contributing/distributing member of bitcoin.

any advice/suggestions/comments would be appreciated! i know this isn't the first thread like this but i will have a sense of relief in my mind if i get personal responses on here lol

thanks everyone