I work in a college with A-Level drama and dance students. I have been using two old MacBook Pros, each with 8GB RAM (just successfully Capital bid for £4K for a new one!):
For exam shows drama teachers play back the projections in Powerpoint (including slides with videos with sound) from one MBP. Mini Dp-to HDMI wireless link to Dell 7760 projector on grid. I agree with Richardash 1981 re: Powerpoint for simple linear projection shows. Set up as he describes it just works.
I do lights (hitting Go button on ETC Ion) with the left hand and sound from Qlab on the other MBP with the right.
I know all three could be combined in Qlab, but the way things come together here, with amateur performers / scripwriters and cue changes right up to performance time, this is the best system for smaller, exam, shows. When we do the annual major production we use Qlab for video instead because of all the additional functions.
Never had a crash in 20 years.
Reading technician-v2's comment I might look at vMix next...