I would support DWS if she runs, but I would prefer to see her jump to a leadership spot in the House. The current House leadership is just way too old.
DWS would be the equivalent of a McAuliffe in a statewide run in that she'd horribly underperform what polls would indicate - except that she'd lose by 5 or more. Sorry, but bland neoliberals are not all they're cut out to be in contests like this.
Grayson would lose by 10 or more; ideologically, he's where we need to be but he comes across as too abrasive and creepy-looking (in a mortician kind of way) to win a seat with 50/50 odds or less favorable. He only won at the congressional level in the first place because of the 2008 wave, and only again because it's a brown, Democratic district.
Graham would be viewed as an opportunist and would lose as well - and of course as has already been mentioned, her seat would flip again.
I think to a smaller degree, both of those elements would apply to Murphy as well. He needs to stay where he is through redistricting at the very least. In 2022, he'll only be 39.
The truth of the matter is that FDP doesn't really have a bench for this kind of run at the moment, so we'll probably lose whether it's an open seat or not.