Please don't think I want Liz to be nerfed because I hate her. I think she's a fine character. The only reason I'd want to see her re-balanced is because I think it would make the game more fun.
You mention Andy as a better candidate for a nerf, and while I agree he's quite strong and has lots of good moves, the difference is that he actually uses most of his moves. If you weaken any one of Andy's moves (uppercut, fireball, elbow strike or kick), it would hurt him badly. Watching most Andy videos, I think you'll notice people employing nearly all his moves in order to win.
Elizabeth's problem is not just that she's strong. It's that her uppercut and uppercut DM are disproportionately strong to the rest of her moveset. Her combination of combos, counters and command-throw SHOULD make her very fun to play and watch (more like Chin, in my opinion), but her combos are just too easy, too safe, and too damaging, so the rest of her tool set just doesn't get utilized.
Call me crazy, but I honestly think she'd be more fun if her uppercut / DM weren't the only thing she did.
Same goes for Raiden actually. No one mentions it much, but I think the characters themselves really suffer from these over-powered moves. They're more fun when they're forced to show versatility.
Well I don't mention Andy in that I think he should be nerfed, but moreso in that I think he's a stronger character overall.
As far as the DM and uppercut DM being too strong, I rarely see her damage coming from a well placed uppercut, or even lucky trades/anti-airs. With the most recent vids posted in the video thread, you see all of her damage coming from her crossup, or just good punishment. Which kind of goes back to what I was originally saying about her being a dial-a-combo simple character. The majority of the time (Or at least it seems so in vids) she is waiting on a punishment opportunity, or hits a well place counter, or a crossup B, and leads into the combo. With that being said, I could agree with making her DP unsafe, but I don't think that's going to make people complain any less.
As far as the DM, again, the damage strictly from the DM seems disproportion to the hate it gets. I could understand more of an argument based on her being too good of a battery, but when I see them hit the DM I just think "I wonder if that meter would've been better off with an EX move" or possibly saved for later. Check the most recent vids and you can see, the DM is not where the damage is coming from. In fact most of the damage I see is from hitting the clean C into whatever, but again, similar comparisons can be made with other characters (Kyo for instance).
I can understand wanting to see her do more, but honestly, with her moveset, there really isn't much else. In a game where random damage can lead to huge losses (Via maxmode/drivecancels/etc) trying a more unsafe approach (say... using more cmd grabs) can make a large difference in whether a character is playable or not.
If anything I find her playstyle to be a little on the boring side, as I myself would mix in more counters and cmd grabs (Probably a bad idea), but if you're going to suggest changes for her, I think something more than "NERF DP/DM!" would be more appropriate. Honestly though, I look at it the same as Kyo.
st. C, f+B, dp C, dp A×2, j.D, qcf hcb+P
or
st. C, df+D (1), qcf+K, rdp+B, qcb hcf+P
The damage isn't that far apart. The important thing to remember as well is how each is going to fair in the match. For example, without meter Kyo is undoubtedly going to be a superior choice, and also (imo) has an overall better moveset and normals. He also has a much more damaging NeoMax combo, as opposed to the mediocre combos Liz is provided with (So far).
Things like that are why I don't understand people continually putting her on the chopping block. There are considerable reasons to place other characters above her, and unfortunately since we only have theory fighter atm, I don't think a lot of those reasons have come to light (if they ever will). Obviously I'm not saying this is how things are, but definitely something I myself have considered.