DE727 is correct as far as my oppinion goes.
There are things I do not like about primary students just the same as others but that is life as an instructor..with 250 hours and a new CFI you cant just pick who you get.
Primary students pros....everything they know about flying is because you taught them, when you see the look on their face after they land for the first time and solo for the first time it is all worth it
Cons...everything they know you taught them...so teach them correctly because they are flying on your ticket, there is no one to blame but yourself. TOUCH AND GOs. Nothing like 8 hours logged in the pattern when it is 100 degrees with 100 percent humidity.
As for safety and risking your life everyday..I just have not seen that, of course the students will do crazy things that have the potential to be very dangerous but if you are on the ball you develop a sixth sense to see what they are going to do that is dangerous before it even happens and allow it to go just far enough to be a learning experience but not to far to be a near death experience. This is probably one of the biggest assets of being a flight instructor.
You say you want to teach UAT/Aerobatics...teach someone to land a taildragger like DE said and you will pray for primary students in a cessna. A taildragger is squirrely enough when you are flying it, let alone someone who has never touched one before. You really cant teach someone UAT or acro if you cant teach first. You need the cessna/piper time and that sixth sense before you go jumping into a plane and putting it in inverted stalls.
The basic moral of the story is that instructing is great and so far for me the ups have seemed to outweigh the downs, you just have to take it in stride and dont be afraid to be humbled.
Of course it would be great to go into a place, a newly minted CFI and say "I dont really want primary but I will take the commercial and ME and Acro students" They will probably look at you like you have two heads. It is no different than someone with 500 hours flying Citations. But of course most people know someone who is flying Citations with 500 TT so you never know..maybe that instructing job you are looking for exist after all.