I don't find chicks hard to care for or subject to dying. Well maybe a little the first 3 or 4 days, I usually sell them closer to a week old if possible, and my customers very seldom lose them after that (except to predators). There are many advantages to starting with chicks, I highly recommend that, even for first time chicken owners. The difference in temperament is amazing. Even breeds not known for friendliness often become extremely tame when handled often, and the friendly breeds will do even better.I don't raise chickens for meat. I've had a few dual-purpose roosters we had to butcher because they were mean, and we did not like the meat very much. I only have chickens as pets and for the eggs.
With that said, I suggest speckled sussex, barred rocks, and buff orpingtons for friendlier birds. We have a few particular ones that are like dogs and love to be around us. I also suggest if you buy from a hatchery, spend a LOT of time with the chickens to develop a bond which will give you pet-like birds. Or (I prefer) buy chickens from a local person that raises them. Chicks are hard to care for and we have lost a few, so I like buying older birds, plus you can tell if they are kind or not, since they are grown.
Oh as far as Marek's... I'm not sure - if you want to be safe, go ahead. I have a few that are vaccinated and some not. Where are you located? There's a lot of us spread around in PA so I'm sure someone near you can help out!
One more thing... build your coop 2x or 3x larger than you think you will need... many of us have found chickens to be addicting, and ended up with WAY more than we planned