I'm going to disagree with you on something. Training the overly complex things can enhance your timing for the simpler skillsets. Do you know how the guys that can pull off the complex skillsets learn how to do it? Reps.
They train it enough and get the reps in while they're at the gym. It becomes part of their muscle memory and then they get the timing and spontaneity of it set in while they spar.
A wrench might work but why not use a ratchet.
The problem is no one spends the time repping things like they should. If you're going to learn to superman punch or spinning flying wall kick with a twist and a somersault into a steven segal aikido wrist lock... You can't throw it in once or twice a month when you spar. Drill that shit 200-300x a day for a week or two then get back to me about whether or not it "works".
You fall back on the less complex stuff because that's what you've drilled the most.
You fall back to jab lowkick because you've done it the most. Even the most complex combination is going to have probably a jab lowkick somewhere in there. When have you sparred and never jabbed?
That's like guys that never practice rubber guard but want to try and throw up a gogoplata for shits and giggles when they're in trouble then say "that shit doesn't work!". You HAVE TO PUT YOUR TIME IN.
I'll reserve judgement about that stretching comment till I see the post you plan on making just because it would be unfair to say something until i see everything. But I'm going to just say stretching is an important part of mobility work that gets a really bad rap. It just all depends when and how you use it.
Next... I'm sorry bro but if you want to get good. 5 days week. Minimum. Skipping days so you can get in time to lift is fucking bullocks unless you are just doing muay thai as a hobby or to stay fit.
Neder is right that most guys go far too balls to the wall hitting the pads especially when they're new and can barely remember to keep their hands up. But after you get past that point the only way to mimic combat well enough to improve your fight endurance is to really go hard on the pads. A good padholder isn't just going to call out combos for you either. You'll have signals so he can just hold the pads and have you spontaneously react to what is there. My coach calls it "see and hit". This mimic's a fight so that when you see an opening your reaction time is such that you respond immediately and hit that shit. calling out numbers and such is fine but you have to get passed that, he should only be calling things out as needed. Also a good pad holder is going to fight back. Hard.
Imo they shoud be wearing shinguards and have the thai pads that have a bit of cushion at the top so they can punch back at you. If you drop your hand they can fire so you're self correcting your technique as you go along.
Oh you got hit? Apparently bad defense. Try again.
Pads should be rapid succession...
hold pad up jab,
they throw a kick,
you check it,
the pad is up you throw a right hand,
pad is up again,
you quickswitch left kick, plant that foot,
pad is already there,
left hook- right hand,
as soon you re chamber they throw a straight right you roll under it,
pad is there so you throw a shovel hook, hook to head,
pads are down so you clinch throw 3 knee's, release, spin them out,
pads are up AGAIN,
your partner yells "DOUBLE",
you throw a double kick,
partner yells "TRIPLE!",but places the pads on the other side,
boom you switch and throw 3 kicks,
they put up the pad you teep.......
and it flows hard and fast for the length of the round. Random, spontaneous, attacking and defending. Pushing, moving, using your footwork. Forcing you to be fluid and perfect in your technique.