This seems like a very common topic where shoppers ask about taxes.
There are many wonderful posts out there already that should be stickied and a dedicated forum is the best place to stick em!.
If I have a question about taxes, the first thing I do is search on the term 'Taxes' and have to go through gobs of posts, several of which someone happened to mention taxes but is not really the thread topic. Eventually I find the really good posts. However, I see the same questions and discussions coming up over and over - having a single forum would help avoid redundant threads.
If allowed, it would also be a great place where shoppers who are also tax preparers or have a favorite tax preparer could let other shoppers know which region they work in and are available to assist. I know mystery shoppers would like to be able to discuss their tax situation one-on-one with someone who has experience in mystery shopping and can provide advice on the financial aspects of their business.
Things I've been learning about but took a while include Home office deduction, commuting vs. work mileage and other deductions, hobby vs. business, Cash vs. Accrual accounting, getting an EIN and its impact, and more.