Trust me
The fact that an item is premium doesnt mean that it is good
For example i used premium legs like 4 times to make a mythical why you ask ?
Because they are trash
Massive feet are the best legs in the game currently
Go for it! If you want to ease into it, rank up mid week. Arena gets easier later in the week because as you said, you get matched with comparible mechs, and more mechs make it through the threshold as the week progresses.
The first few days will is nothing but beats, then mid tier mechs, then the mechs who scraped by from pure luck.
By the way, good reasoning behind your modules. I have one mech dedicated to heat and two generalists. Playing the odds is more realistic than making a perfectly rounded mech.
I only use Squinch because i didn't have too much extra weight for a drone, and Squinch is pretty light with that 22kg. I have Backstabbing protector and Heatpoint, but i did not use them because of weight problem. Otherwise i'm praying to get the amazing Swoop. I thought about replacing Corrupt light with Flaminator (i don't have Dawnblaze), but my only concern was when i fight against energy mechs it's gonna hurt me when i use it, since it uses good amount of energy. I'm still gonna swap it out soon tho. I dunno about which module do i myth first. I think my biggest problem (not counting that having no pys shield) is the small heat capacity/energy regen.
your mech is very decent and looks fun, except the drone part, farm for fortune boxes and try getting drones such as Nemo, Backstabbing Protector or Firefly, and transform your legendary items to mythical in the process.
Hammer won't serve many purpose but it seems like you want to make good use of Red Rain so you can keep it, i would replace Corrupt Light with Dawnblaze or Flaminator, when transforming legendary items be sure to priorotize mods or Abomination, it is a really nice side weapon