It is much easier to learn a proper technique to get out of mount in the first place and adapting it to MMA environment afterwards. One shouldn't learn things doing it in half-measures.
It seems you have not yet understood the main premises of BJJ, which hold in MMA as well:
1. Position before submission
When you are in a weak position - like being mounted - you have to fear that you are subject to ground and pound, yes. But it is not the ground and pound which should be your main concern, it should be your weak position. It does not matter what you do or what your opponent does. As long as you stay in that position, you cannot hurt them and they can hurt you. That is why your main concern is and has to be getting out of that position.
2. No compromises - effective technique or nothing
One may well think about a thousand possibilities and try to embrace and secure oneself against all possible kinds of attacks, but truth be told: you can't. Think about knife defense as a different example: Yes, you could think about a gazillion ways of effectively warding off the weapon and disarming the aggressor, but in truth, that is not your main goal: It is surviving and the best way to ensure survival is disabling the aggressor as fast as possible. Yes, you try to block, sure. But you will be cut or stabbed anyway and you will survive most of it for long enough to get help, but if you don't stop the attack, you will accumulate wounds until they become lethal. Therefore, you accept that you will get hurt because you are in a bad situation and carry on with getting out of it. It may sound paradoxical, but attack is your main focus here.
The same is true for mount: Yes, they will try to beat the sh*t out of you and you will not be able to fend off all of these attacks anyway. Therefore, the sensible thing to do is to use the most effective way to end this problematic situation with all your focus and strength, and as fast as possible. The most effective way to do so is what you learn in BJJ. Starting, it will take you what feels like ages, but with experience and body development, you will see that it becomes much faster. Even if you get hit a few times, it will still be less damage than what you have to expect if you just defend or try other (less decisive and effective) ways to get the hell out of there.
Having said this, you oversaw a major point here: Once the balance of your opponent is compromised, they cannot possibly do any effective ground and pound. Even if they hit you, it won't hurt that much, since they cannot generate power.
This holds true for probably any problematic aspect you made out. In every other one, either adding a guard is no problem, or your opponent is in a compromised position from which there are no powerful blows possible and they would risk counters which bring them in peril themselves.
Having said all this, it is helpful to train the situations and techniques with strikes allowed as soon as you gained some proficiency in applying them. That's what your MMA sparring sessions are for.