Is there a maximum range when it comes to using the two team abilities? Does it have a maximum range of 10 just like outwit and perplex or can it exceed 10 range as long as there is a clear line of fire?

Presumably it's as far as the character taking the shot has range for, so long as the one or more accompanying Hydra/PD pieces have a clear view to the piece, even if it's beyond their individual range. They're not taking the shot, after all, just lending some aid/advice.

This is just coming from a player, though, but I've seen many 6-range Hydra/PD pieces help out 10-range pieces, so it appears to be supported.

There is no range limitation. It only requires line of fire.

So if somebody uses an Icons veteran Darkseid(12 range),who has an adjacent friendly figure with PD ta(who also has a clear line of fire to Darkseid's target),he(Darkseid)will be able to benefit from it right?

Right. And it will work even if you increase Darkseid's range to 15, so in theory the Hydra/PD figure could be 16 squares from the target...