I recommend the Tulip brand of puff paint, very reliable and looks great on suits. There're two versions as far as I'm aware, the puffy kind is a matte color while the slick kind is shinier. If you want the webs to last longer and not break or crack as easily, you could mix it with some Liquid...
I think plastidipping the webs on would be a lot more effort than just getting some puff paint and tracing over where you used the sharpies but that's just my opinion. I haven't heard of anyone using plastidip for the webs but it could work.
Awesome cosplay! I've only ever seen Luke101/@do_you_even_cosplay do a really great MoCap Mysterio along with MCU Mysterio but I think yours is pretty good considering it's handmade.
EDIT: @swagatron42069 on Instagram has also done a really cool Mocap Mysterio along with a pretty darn accurate...
Do you have any tips on how to eat without taking off your mask all the way? Whenever I try to do it the lenses touch my eyeballs or the lenses go further up my head.
If you want the webbing to look a bit neater, I'd recommend using an applicator bottle/tip. Much more precise and less likely to spill any puff paint on the suit and ruin it.
If you're doing the Nano Gauntlet for Iron Man, its basically just the Mark 85's right arm and hand but the fingers only go up to the first joint. They're also a bit different from the normal fingers. Here's a picture of what I mean: