Yes I would recommend insurance, as Atom says (cracking dogs btw
) ears and skin are a big issue for GSDs. As the ears stick up all the time they are a complete target for muck, dust, grass pollen, toy soldiers, small children...it all get stuck in there. Get your dog used to you handling and rumaging in it's ears to clean them out if necessary, and try to avoid walking them in long grass if it does look like they will have a problem with their ears.
Having said that, there will be a genetic component to that as well, my previous (and first GSD) used to have really bad ears, he had waxy buildup all the time and we were forever putting ear drops and wash in, which he wasn't best pleased about...but the two I have now (so far) don't seem to have any issues and they are in the same place and get walked in the same area as well.
They can also be gluten intolerant so you may have to be careful what you feed it, avoid wheat products (I stress this isn't all of them, but there is a significant number), if they are intolerant they have upset tums all the time, poor things.
Whilst we are talking of tums, don't let your GSD bolt it's food, they can be prone (as all big dogs can) to what's know as gastric torsion, literally where the stomach twists itself up, if they aren't operated on within minutes of it happening they don't stand a chance. It can be caused by them bolting their food, eating too much, (and open to debate if you read the studies) running around soon after eating. Again depending which study you read, it seems it may be best to feed them so their bowl is on a small step so they aren't reaching down so far to it...it's a contentious issue though.
Finally with their food....GSDs, especially puppies are very keen on recycling...eating their own poop. It's a general thing with dogs but GSDs particularly, not the best to have a friendly dog try and slob you after being outside and getting this horrendous smell from their breath, shouldn't be a problem if you walk them regularly and have a good routine for them though.
As already stated, hip problems are an issue, elbows can also be an issue.
Generally they can't handle a lot of protein (delicate tums again).
I wouldn't say hip scores are meaningless though, obviously if you are getting one from a rescue (as one of ours is now, and our previous one) then it doesn't matter, you fall for the dog not the stats.
However if you are getting a pup, a good hip score is a useful indicator of whether the dog is going to have hip issues in the future, if the parents have good genetics and good hips the pup probably will as well.
German Shepherds will get on with ALL dogs....but unfortunately not all dogs get on with German Shepherds.
My first one was attacked several times by smaller dogs, including damn fiendish Jack Russells. Because of this GSDs can react badly round small dogs out of fear and vice versa...also when you walk a GSD you hear stories from worried dog owners about how their little cherub (never said boo to a goose) was savaged by an out of control GSD and is now scared of them...I'm sure this does happen with irresponsible GSD owners, but we have seen so much aggression from other dogs it's certain to be the other way as well.
Best way is to get it out and socialising as soon as possible.