Also, just to add, I can't remember 100% but I am pretty sure there was something I could tick after I put "no" to all those mentioned above that stated I was exempt but it's not showing up on the copy of the application I have so I can't remember fully (as I might be confusing it with my ILR application that I did just before this one).
Also, you DEFINITELY don't have to provide your P60 if you're a regular full-time, salaried employee. I didn't have to provide any of that (just my NI number).
Honestly, I would step away from the application for a day or two to clear your head as I think you're letting yourself get frazzled by this and you won't be able to do yourself any good if you're trying to fill it out with a frazzled brain. Just remember that you're basically at the finish line so try to just "deep breath" it.
I definitely agree with Ksand that this was definitely the easiest out of allll the applications I've done thus far. Less evidence required and it was more straightforward than some of the other applications in the past. I'm not sure how you managed to get sucked into a bit where you're being asked to provide even more details than should be necessary

perhaps they changed the application a bit since I applied but it's only been around the 2 month mark since I did mine so I wouldn't have thought that'd be the case (but might just be unlucky). You absolutely do not need to take any language test or provide any additional information to the best of my knowledge.
Happy to walk through it all with you if you want to PM me? Don't want to put my entire application on here but I can help you more one-on-one if you want in a PM.