A - I had a tough fight and am stretched on resources. I go to camp expecting a rest and get wiped by a random encounter.
This ties back to resource management which is a big thing in 5e. You took a risk, in adventuring for longer, and then couldn't make it home. In the future, you'll consider the risks of pressing on when you're almost spent, which imo is more interesting than just continuing to adventure until you're out of all resources. However, in order for this scenario to be really impactful, we need to be able to short rest more than once. Currently it is too easy to lose all your resources.
B - I am full health and want to go to take a long rest. Perhaps I want to talk to a companion that said they will share some info with me at camp. I get random encounter, wipe the floor with it, just spend 10 minutes accomplishing nothing.
Again, resource management. In the future, you'll weigh going back to camp when you're full on resources (and probably full resting) with the risk of getting a meaningless fight. This will help balance the long rest vs short rest-based classes, making it so you can't just spam long rests. Although I agree that random encounters should grant some XP/loot, so it wouldn't be entirely meaningless.
I think the key point of any "random encounters" added is their randomness. You shouldn't get an encounter every time you travel back to camp. It should happen occasionally, but with enough frequency that it affects your decisions on when to return to camp and rest. If you make the 'optimal decision', then any random encounters become your option C, where you have some resources left and the fight is challenging and enjoyable. If you take a risk, then you might get punished for it.
