That is an often debated question. You can log the sim or FTD time and count it towards total time per the regs. Now if you have 1000 hours and 100 to 200 sim or FTD time, you might get some funny looks in an interview. I had some good advice a while back that said " if it does not leave the ground then don't log it as flight time." As far as something being okay with the FAA, well lets just say the Feds usually do not have a real world view things. As you get further in your career, you will see what I mean. The best idea I have heard is to have two logbooks. One for sim and one for aircraft. That way is you are 100 or so short on hours for an ATP then you can say I have the rest in this logbook. Good luck.