That's a great question :D. It really gives the chills when I heard something that sounds dope. It just clicks. That's a great feeling when you hear a new songs and it's so dope that you want to listen to it again and again. Can anybody relate? :D
1. As long as the beat is hot it can be boom bap or trap.
2. To me lyrics aren't that important I am listening to the beats more. But I mostly like story telling type lyrics and lyrics that teach something new. I don't really like braggin' type lyrics.
Selling beats is nothing new. People have been selling beats in the internet for years. I think it's great to have your own website where you can showcase your music and sell it. As a producer you deserve money from the beats that you make. Selling beats is good way to get money from the beats...
In my opinion the easiest way to learn producing and making beats is just start watching YouTube videos and learning your DAW By that way. I don't think you should buy lot of hardware like mpc and stuff like that because softwares do the same thing that hardware do. I think investing in studio...
Music Centro is free http://urmc.co/ and Beatstars too https://www.beatstars.com/. You can also start collecting emails from Twitter, Datpiff and etc.. and start trying to connect with artist/rappers and form a relationship. People usually need to trust you before they are going to buy a beat...