Apply online surely
Dont need to sign, the acrobat forms validate themselves just fill it out then hit validate
I uploaded my police certificate with my explanation letter, I dont know if it was needed even. But yes I didnt upload any educational docs, not even IELTS score. But I say you mention good academic standing in SOP and also if you got a good score put the figures in SOP in a way that it supports your case.
I will say from my experience, get medical done from before, its not that costly and you will save one step of the process once it starts, I didnt know this and I had trouble getting appointment in the right time (though I got it after much hassle with IOM)
Must apply fr TRV, when you apply online thats the ease, you have no chance of missing out something essential, TRV application comes as a mandatory doc on ur cic portal when u apply online.
They didnt ask me for any additional docs and I didnt upload any, I agree with aammadmi, dont complicate your case
You apply, get your bio done, wait for med call (unless you get it done upfront)
It took 10 weeks for them to request meds, which I got done in 2 weeks, they got approved withing a week and passport also got requested in the same week.
MUST submit a strong SOP, especially if you are changing your main field. Make a valid case.