Well since I already bought some hermits, snails and emerald crabs I guess getting a puffer or trigger are out of the question so I'll be getting a peacefull tank.
Not necessarily. There are quite a few more peaceful things out there such as Niger, Pink Tailed, Cross Hatch, and Blue Throat Triggers that don't often create much of a problem. Puffers on the other hand are really hard to tell. I've seen some idividuals that were calm and didn't touch a thing, but I've seen others that ate everything in the tank.
Pink Square Anthias or Dispar Anthias - I would like to get a school but how many and would it work in a 75?
I would aim at keeping one, and no more than three in a 75g tank. I've seen people with more, but they normally have limited success with that amount.
Mandarin - Must have but I'll wait till the pod population is up.
Good choice in time.
Lieutenant Tang - Would my tank be too small?
This grows far too big and would demand a large amount of room. Tang wise, you're best options are Yellow Tang, Scopas Tang, and Kole Tangs as commonly found in the trade. If you're lucky, you might be able to find some Kole Tang cousins such as the Tomini Tang that stay rather small. Honestly, of all the smaller tangs, I prefer the Kole Tang.
Pair of Percula Clownfish - Would they be ok without an anemone?
This would be a great addition with lots of personality. They will do fine without an host. Most likely they will eventually find something to host in that isn't an anemone. You've seen my ocellaris rubbing on various corals.
Six Line Wrasse - Maybe
A good choice, but a few people find these to be aggressive once they are firmly set in a tank. These are normally better as one of the last fish in the tank just to play it safe.
Fridmani Pseudochromis - Too aggressive?
IMO, far too aggressive for smaller tanks with peaceful fish. I rate Pseudochromis up there with Damsels as far as aggression goes with reef safe fish
Jawfish, Yellowhead - Thinking about getting 2-3. Would they be a problem with the mandarin?
I would only get one. Maybe two if you feel lucky. It shouldn't have a problem with the mandarinfish. I would add this guy a little later in the tank to make sure your sandbed is settled down. You'll also have to be careful that it won't cause any avalanches buy burrowing under any rocks. It could use a slightly deeper sandbed than you have, making the sand deeper in some areas will help alleviate that.
Marbled Bamboo Cat Shark - Just to make things interesting j/k
You and me both
What do you guys think? Too much of a bio load too little? Pretty much the only must have is the Mandarin. This is just a basic idea of what I am looking for.
I think that, if you were to get all that is mentioned, you would be fine on bioload. I think that the clownfish and mandarin are a good choice. The six line will compete with for food with the mandarin and runs a slight risk of being aggressive later on, but a decent choice. The Anthias isn't bad, but make sure that they are eating well in the tank prior to purchasing. They need a fair amount of room though. The Jawfish is a good choice. Those 4 fish (not including multiples) should be fine.