in more extreme situations I've had to side-slip the aircraft to use the airframe itself to increase drag.
typically turbine aircraft shouldn't be side slipped. The risk of inadvertent engine failure exceeds the benefit of slipping. Or at least that was the airline's policy. Depending on the realism a simmer is going for one might want to avoid slipping turbines - but thats only for the hard core realism gurus
most turbo props can use reverse thrust in mid air, i do it all the time with my C-130. Slows down quite nicely.
Some can, some can't there are arguments for and against this. I knew a guy in an early king air that did it frequently until he was asked "What happens when one or both engines doesnt come out of reverse?" thats an excellent question.
Or take the SAAB 340 for example... catastrophic engine failure will result if reverse thrust is achieved in flight. (SAABs are now equipped with a flight idle stop to prevent this due to an accident wherein a pilot attempted to use reverse in flight) again... depending on what your realism preference - going into reverse thrust in flight might be "cheating"
- but there
are aircraft that can do this, like you said.
just my .02