Yup, Carapace is the IG's heavy armour.... Even if her set is in rough shape.
That assessment would also make her the only CQC combatant of the team as well.

Well technically a sergeant is good at that as well and he is wearing carapace as well. He has a power sword. And I am assuming colonel is decent as well simce his backup is a saber. What is your load out?

Welp, Lasgun, Combat shotgun, Auto-pistol and Chainsword for her weapons
Carapace-Full set but damaged due to neglect.
Also, Frag and Blind grenades.

Thats alot of weapons to carry lol. Maybe I should add bolt pistol, frag and krak grenades. Do guard have melta bombs? Also whatbare some of the rarer weapons guard troopers can have? Do we get a chimera? And who would be closest to a good pilot for one?

Bare in mind that although carapace is technically the heaviest armor a guardsman can get it is still by 40k standards considered light armor for the purposes of taking shots you are the same as a space marine scout in terms of armor. Since armor is such a big thing I am amazed no one went for Techpriest Enginseer which I made available to take and also comes with power armor and a power axe as standard.

Nobody want to be the that kid picking the most overpowered character eh?

Guardsmen can take frag and krak grenades, they can also take melta bombs but this places them firmly in the demolitions category more realistically they have demo charges which have more universal application. rarer weapons for guardsmen is technically the sort of things I listed like hellguns hotshots, power weapons and certain special weapons like melta and plasma.

Vehicles in the 19th Valerian are extremely few but do exist although most of the time you will be footslogging it.

Andy & Simmy are the most light-weight in the group, I think. If we went with tech-priests, though, we couldn't do the sniper bros team, though.

Im surpised Zeth wasnt going for tech priest. And it looks like our only special weapons are snipers. I am thinking our squad should readily break into two teams each with a sniper, colonel and me on opposite teams and heavy trooper opposite of void born.

We are literally a sniper team, dude. They operate as two halves of a whole.