Just increase your rank if you be full member you can join to all serivce at service forum and earn more than 50$ weekly easy
I believe anyone can accept Bitcoin for services offered even outside the forum.
Its not a must you will have to join the forum services section before you can start offering services and getting paid.
You can create your own website, offer services and get paid in Bitcoin. But dont accept only Bitcoin, make it easy for your clients to pay with their favorite payment method.