Can you gimp your character by insufficiently planning your passives?

Solution 1:

It is very possible to create a character that cannot proceed past a certain point. It's even expected that you'll eventually reach that ceiling. Path of Exile focuses more on reaching the end-game than surviving it. As of this writing, the highest level player is only level 84.

Class ultimately doesn't matter, but there have been numerous reports of melee being less viable than ranged classes in the 60+ level range.

Don't worry too much about your first character, mistakes are almost inevitable. Just take notes of what seems to work and what doesn't, and you'll have a greater understanding of the passive skill tree in no time.

Just remember that PoE is designed to be unforgiving, and roll with the punches. Above all, have fun!