Even if Sun is up; Mon taking 2*, and 4* damage from Fire attacks should be able to beat us?5.) What pokemon should pressure and/or beat Cap24 regardless of weather being active?
CAP24 isn't going to appreciate taking priority hits of any kind barring maybe Sucker Punch and Aqua Jet. This means mons like Mega Pinsir, Mega Scizor, Syclant, Cawmodore and to a far lesser extent Kitsunoh and Necturna are going to be able to beat us around even if weather is up with a speed boosting ability. Volcarona generically pressures everything and its STAB is super effective. Focus Sash Fidget can pressure us out if it carries a Poison move. Mega Venusaur completely decimates it with Sludge Bomb and takes no damage from our STAB. Necturna can presure it with super effective coverage and can pressure with Shadow Sneak.
0 SpA Shiinotic Hidden Power Fire vs. 252 HP / 148 SpD Scizor-Mega in Sun: 204-244 (59.3 - 70.9%) -- guaranteed 2HKO
That's on a Shiinotic. Put it at something like 125 SpA, and 252 Investment, and it's getting OHKO'd after Rocks in the Sun, without Life Orb with a HP Fire. That's a big statement to be making I think to say mon like Mega-Scizor or Syclant can brute force past this mon in the Sun, which has a reasonably good offensive typing.