What browser and OS are you using? In Safari on OSX, it is no problem for me to type in my password with the keyboard, or to simply copy and paste it in.
As for your other gripes: Buying Counterparty assets with BTC is still a pain in the ass. It is recommended that you buy some XCP first (native Counterparty token), probably via a 3rd party exchange such as Bter.com. Then use XCP to buy the asset instead of BTC. This will go through much faster, and doesn't require you to stay logged in. BTC trading is still kind of screwed up, but the devs are working on a way to fix it. The difference is basically that BTC doesn't natively support escrow. XCP and all other Counterparty assets do.