Good job! Homework #1 Done!
Turning pro is a great feature I would say. I know myself a lot of players who are already playing poker everyday for living. And their life is really enjoyable. Can do whatever you want to. ♦ But of course before that you will need to spend a lot time becoming that good.
Easiest way to fight against tilt is to set up stop-loss technique. Which means if you for example have lost more than 3BIs for a session then you just stop the session for some time. The BI amount is set up from your own results. Some may put it higher, some lower. Also after the stop you can spend some time with evaluation part to become better.
Playing too many tables is just horrible. You wont concentrate playing solid poker or either playing against opponents. You will just play your hands and that's it. If you are good at playing a lot tables and have great winrate then why not to use the strategy of multitabling. But if you rather are new to poker I would strongly advice to concentrate on the play and play less tables. Get the understanding of poker preflop/postflop play and what is the correct play and what ain't. Usually it's the opposite to making money with playing a lot more tables if you are beginner. You will do a lot more mistakes with it.
What do you mean by trying something new? New variant of poker or something like loose play? If it's a loose play then I would strongly recommend trying to stick to the basic play and learn it first. Later on you can always adjust your play and widen up according opponents.
Position is the most important thing in poker. That's as well the reason why actually our chart advices to play less hands OOP and rather more hands IP when it will be much easier for you. You will face way too many hard decisions, could be very expensive leak.
Stealing can be very profitable but when you don't know against who you steal or how you gonna win the pot either preflop or postflop then it will become more harder. You will still need great postflop skills like to know where to CBet and where to not, which boards are the greatest to CBet, which opponents and etc. Rather keep it tighter if you are still playing MSS, although BSS allows to do a lot more adjustments.
Welcome to the Course and Best of Luck. Some more points earned.