On another point, it should cost much more to repair wear & tear over battle damage. If you take a laser hit that punches a hole through your hull, all you have to do is slap on a patch or replace a hull plate. That's pretty simple work that a monkey could do. But if the integrity of your entire hull is down 10%, you need to fix the entire hull! I could see this needing special equipment to repair your hull on the molecular level and a lot of time to do it. So, yeah, it should cost more, but not more than the insurance cost to blow up your ship and get a new one. That's just g stupid.
No offence, but this is nonsense. The truth is you can make anything work in sci-fi, because you can just invent a reason for it, but this is far from logical. The problem is, FD aren't thinking like engineers when it comes to ships. Let's compare with a real world example: cars. A car exists in a relatively hostile environment. Exposed to constant erosion, friction, chemical reaction within the environment. These effects take their toll on a car over time - namely, corrosion. None of them weaken the "integrity" of the vehicle in any appreciable way, not in reasonable time-frames of ownership (decades), rendering it more vulnerable to physical damage - i.e. crashes. Indeed, you NEVER repair this damage on most vehicles, because it involves stripping the car right back and repairing the structure by welding new bits on, making new panels, etc. I'm ignoring wear and tear on things like pads or clutches, because that's not analogous to what we're talking about here - those are part of "module" wear and tear. So, the truth is, other than going through consumables, like those mentioned in the previous sentence, new cars require almost no money spent on them to maintain their structural integrity as a consequence of wear and tear. Now, you might say "but, SPACE, man!" Yeah, space. Big, 'ol, empty space. There is no corrosion, because there is no atmosphere. There is no physical abrasion (we'll come to micro meteorites and debris separately), no water. What there is, is radiation. So, one might expect some tiny amount of your hull turning into some other material due to nuclear reactions over a long period of time. This would be negligible at the best of times, but shields surely render it completely inert. So, what about bits of crap lying around in space smashing into you as you fly about? Well, this is what I mean when I say FD aren't thinking like engineers. This problem HAS to have been solved in order for space travel to be practicable. Maybe it's solved through shields, or maybe there is some other field a ship generates to push small objects out of its path as it travels, but either way, if this debris is out there, it's hitting you, and it's making holes, your ship isn't going to last a single trip anywhere.
Conversely, a few weeks ago, I was.... "interdicted" by a badger on a country road on the way home. This cost me almost £1000 to fix. Yeah. Battle damage from the badger cost me more in one sitting than I have ever spent on maintaining my car's structural integrity.
I also think there are some question marks over what exactly hull integrity IS. What are these molecular repairs that the hull requires, which are somehow more costly than giant holes carved out of it by weapons fire?
The truth is, no one would design and try to sell a car which cost us £/$/€200 for an hour long trip. No would design a space ship which requires such a large portion of your income just to repair damage in flying from one place to the next.
Now, planetary landings are another matter. Managing damage during those could be interesting mechanic, and expensive repairs a necessary evil. That makes perfect sense, and it doesn't punish people for NECESSARY travel.