Ahh yes, the sand is a bit of a pain like that. It's going to try and level out over time. I have pool filter sand with some arogonite mixed in. I usually have to do some landscaping every or every other time I do a PWC. I've found it helps to get some rocks to act as barriers but short of building an actual wall with them, I still get the leveling out effect. The water does get cloudy whenever I drudge it up like that but it usually calms down in 10-15 minutes.
Feeding them is really easy. The skippers eat pretty much
everything. The crabs will definitely eat everything the skippers eat. The crabs eat all the tiny stuff that get's built up in the tank (including what the messy mudskippers don't finish) but I still try and give them their own food ever other day or so. I've fed them all frozen bloodworms, krill, brine shrimp, mysis shrimp, marine cuisine and I think a few other frozen items. I throw the occasional algae wafers and crab pellets down for the crabs/shrimp and sometimes the skippers even go after that. They are really easy to feed. I hand feed (well finger feed) the skippers too. That way I know the bully doesn't eat everything. I've even hand fed the male fiddler a few times. As for live food, I've given them crickets and fruit flies. I have seen them eat an occasional ghost shrimp but all in all, I think they are too fast to catch in the deeper water. I like to add live food every so often to keep their natural hunter instincts active. Fruit flies are pretty cheap and really easy to breed. Let me know if you want more info on that too.
One LFS around here had some of the larger mudskippers for a while this spring but they didn't have them this past weekend. Other than that, I haven't seen any LFS with any others. I got mine from Franksaquarium online. Paid through the nose for shipping (about $36 I think) but the service was excellent and they were only $7/ea other than shipping. All three were just little babies when they arrived but now they're full grown. I think Frank's is out of stock now but you can certainly email him up and see when he expects to have more in. Well worth the price if you ask me!
Not sure what your LFS are like but I've pretty much hit up everyone within the metro area here looking for everyone that I wanted. There's about 4-5 places around here that have fiddler crabs and they were usually <$5 so they weren't a problem. Petsmart is the the only place I've seen the RC around here but from my research, they're more aggressive so I decided to stick to fiddlers who haven't been aggressive at all. Plus it's fun to watch the little guy waving his big claw all over the tank
. I hate to say it, but I've seen them at Walmart so if you're out of other options, you can try there. Definitely let me know if you go with the RC's, I'd like to know how that goes.
Also speaking of Petsmart, that's where I get some of my ghost shrimp. Once you get up and running, it might be worth grabbing a few of those to help clean up and maybe give your skippers a treat. They're only $.30 and they're pretty fun to watch as they comb the depths of your tank for food. They also eat all the same foods as the rest of the tank mates.
