First of all, you made a great move by listing out your stocking list and consulting people BEFORE putting them in your tank. So many people just buy the fish and shove them in the tanks, and then ask us "Why are my fish dying?"
Second, welcome to the forum!
Third, your list is a tad overstocked. True, cichlids are aggressive and your tank is too small for Kribs as they need a minimum of 50 gallons. Have you looked at Bolivian Rams, or German Blue Rams? That set-up may work however if you add real plants, and a lot of them to break the line of sight across the tank for fish to hide. You will need sand for the cories, and they need a minimum of 6 as they are communal fish. I would say do 10 tetras total. So I would pick one of those types and go with that. Maybe 12 anticipating 2 do not make it. Keep in mind Endlers are like guppies and reproduce like crazy. And you need 3 females to every male, or the females will be harassed to death, unless you get all males. That is fine.
Another thing to keep in mind, our advice usually will be better than your LFS. Their advice has an endgame, to make money from you. We do not. I get no financial compensation from helping you. Right now they are trying to get you to buy 27 fish. That is a lot for a 29 gallon tank. Remember the 1 inch of adult fish per gallon rule...
Also, really read up on cycling of aquariums. Definitely do not add all of those fish at once. Ammonia will spike and kill everything. Tank cycling takes 6 weeks.
Hope this helps!