Ehhh I think we can happily just swap it out for "good grades and haven't left education early"

Could you be a sorcerer if you're related to the DM?

I can definitely be a bard, druid, or wizard and I can maaaybe swing fighter or paladin depending the GM. Particularly for fighter. Fortunately for me I love bards and druids. I don't think I can figure out a coherent bard/druid multiclass to truly be a self-insert, but I may have to try

Oh shit, I can be a wizard as well.

Depends on how they express the anger and who else is in the group, I suppose. One of my friends gets angry at games quite easily, but he doesn't take it out on anyone else and can accept a ribbing from the rest of us about it, so while it's a little annoying it doesn't ruin the time spent with him

Hmm, some of these work. My DM does enjoy that good grass so there are some sessions where I could steal his entire box of dice without him noticing. Rogue it is, then!

Play the music from tape while miming on the instrument. Surely, acting falls within the scope of bardic abilities!

I can be any of these except for fighter just because I don't really want to kick my best friend's ass. Then again, he is pretty scrappy, so like, I might end up getting my ass kicked instead if I tried, so either way, it's a wash for me.

DM: Must have a god complex.

Complex? I find it quite simple

I don't know any instruments (yet), but I can bring a vuvuzela and learn real quick during the next session

Depends on if it's a bloodline relationship. Handholding types get to be warlocks or clerics

“It’s absurd, we have a play group of 20 and they are ALL WARLOCKS.” “My patron is Geoffrey d’Bezos, an arch fiend!” “SHUT THE FUCK UP RAYMOND!”

i see a party of 5 fighters incoming soon multiclassing into rouges after putting him down a notch together

Would bard-warlock multiclass just be that one Bo Burnham song about Jeffrey Bezos?

Aztec death whistle would also be interesting. IDK how hard it actually is to produce that sound and it's definitely harder to find (or make) than a vuvuzela, but you certainly don't need to know any music and the effect is really impressive.

I inherited my fathers sword, shield, and cloak, so maybe sorceror? Is there one that uses weapons like that? I haven't played one in ages.

Commoner it is unless my GPA from over 20 years ago counts

Multiclass Fighter/Mage, yes. 

Nah, some people have short fuses, some have very particular things/scenarios that set them off. Just don't step on their feet, and back them up if someone's pushing their buttons accidentally/on purpose.