O designates the original, P designates your emendation, ✲ marks an unacceptable sentence, and ? marks a problematic sentence
O ✲If you had followed orders, you would never have to face it.
P ?If you had followed orders, you would never have faced it.
P is grammatically correct but semantically incorrect. The have in O is not used in a perfect construction but in the construction HAVE to = 'must'. Two correct versions are possible:
If you followed orders, you would never have to face it. (non-past unreal)
If you had followed orders, you would never have had to fact it. (past unreal)
O ✲If I would have known this would happen, I would have just done it.
P If I had known this would happen, I would have just done it.
Would have in O is a hypercorrection of the sort often called "footballer English", because it is characteristic of athletes who in interviews or in the broadcast booth are (quite unnecessarily) anxious to avoid the "improprieties" of their native dialects.
O ✲If they were using this as a stronghold, I would have figured they would be putting up more of a fight.
P ?If they were using this as a stronghold, I would figure they would be putting up more of a fight.
Without more context it is impossible to say whether O is incorrect, much less where. Your emendation is grammatically correct, but it represents just one of many possibilities. By way of balance, here's a conjectural expansion in which O is correct; it assumes that the "figuring" is superordinate to the conditional expression
You thought this is where they were holing up, and the loot was buried here. Well, you were the brains of the operation and you were doing the figuring; but if it had been me, I would have figured that if they were using it as their stronghold, they would be putting up more of a fight, to get the loot back and cover up the evidence.
In any case, figured marks this as colloquial, perhaps even dialogue, and colloquial usage is not so demanding as formal.
O ?If they were destroyed, people will become restless.
P ?If they were destroyed, people would become restless.
Again, I think you are assuming too hastily that were represents a present hypothetical rather than a simple past. Here's an expansion where O is correct:
If we can find the papers that back the Chancellor's story, there's nothing to worry about. But if they were destroyed, people will become restless, and the government may fall.