Definitely, definitely take practice tests! Taking them will answer a majority of the questions you asked above. Instead of asking random people on CC these questions, find out yourself with practice tests.
With all the practice you’ve had though, I think you can do it! I didn’t do so hot on my SAT (just a little under yours) either but ended up with a great score anyways on my ACT (34). Turns out that the ACT was just a better fit for me. If you’re good under time constraints, can read fast, and prefer the more straightforward questions (but lots of them) ACT is the one for you IMO.
If you have trouble with time constraints, I’d recommend to practice especially on the science and reading section. Science is incredibly packed, with I believe 7 different labs to go through in just (I believe) 35 minutes. I had to guess on one problem at the end because I ran out of time. Time is essential, so during your practice, learn to make the most of it by skipping the little blurb at the beginning of each section and moving on when a problem is taking more than 1 minute to solve.
Also, don’t worry too much on vocab. You don’t need it for the ACT English portion. However, know your grammar rules and the way things are meant to be phrased. Phrasing is HUGE as you’ll be given a large chunks of reading with words/phrases underlined that you’ll have the option of changing or leaving as is. The reading portion is more analysis and being able to pick up details from the text, so no vocab really needed there. If you read a lot as a person, you’ll do fine.
You got this!