For apex raids, attack minimum is ~2500 ready.
None, but you can do unique Raid such as phoru, indo, and paraT
ideal setup when you get there is 125 speed 3k damage or as close as you cna that gets you into any raid that uses thor,something to aim for
I would second that but keep speed at 123 just in case you need to raid with a dmg booster like tryo, or the best strat for Andrew which requires thor to be slower than skoola. However, there are a few niche strats that 125 is easier to find pairings with thor - a couple of mortem + thor strats. However, you can still do those strats with a 123 thor as long as mortem is slower.
Not too fast actually, it’s recommended to keep it 123 so it won’t go faster than the creatures supposed to buff and cleanse him up.