Is this too much 4 the bioload?

I would only put in three or four guppies. Otherwise, everything looks fine. It's better to be safe than sorry. Your cories don't contribute as much to the bioload because they eat uneaten food that would have otherwise decomposed. Also, the snail eats algae that otherwise would have also produced more ammonia. Furthermore, the live plants reduce ammonia in the tank and keep it oxygenated. However, the guppies aren't "clean fish", so the safe bet is to start with three of each fish (adding one or two at a time, of course, to make sure you don't overload the bioload), then if they all survive for at least a month, go ahead and put in one or two more.