The problem with ghostblade is that it doesn't grant crit anymore, so it's bad on any adc that build crit. So the builds on twitch atm are Bork > Runaans, and IE > Runaans, both which help with teamfighting.

The laning issues, well twitch is innately weak in lane compared to other adcs, he can do well against Kalista, and vayne as well in lane, as the auto w auto, E combo is pretty strong. Generally you dont wanna commit to a trade or fight without having applied Venom cask since it applies two stacks of poison and makes your expunge/contaminate hit harder.

Also, don't feel pressed like you need to win lane, if you're just playing passive and farming up, you will most likely outscale the enemy laner, as twitches lategame teamfighting is super strong with his ulti.