awesomefrench:

Q : there are some fixed expressions that i’ve seen in French where the subject is understood, but not stated. Three of these that come to mind: “ne serait-ce que…” [even if only…] & “se ferait bien…” [it would do well…] & ‘reste à savoir…’ [it remains to be seen…]. Are there a lot of these in French, and might you know a list of them that I could learn?

A : There’re hundreds and we use them a lot!! It’s called locutions. 

As you said :

• Ne serait-ce que
• Ce serait bien que > “Se ferait bien” doesn’t exist, at least not in that context. “Se ferait bien” is quite a scandalous way to say you like somebody xD 
• Reste à savoir si

Some other common possibilities :

• Autant dire que : You might aswell say
• Sans préciser que  : Not adding 
• Quid de : What about
• Juste pour dire que : Just saying
• D’autant que / plus que / moins que 
• Histoire de : -No translation. Ex: Je passais histoire de. > I was just stopping by. 
• Autant que faire se peut : As much as possible

Here you can find all the locutions.(There are different links for every kind of locutions…) I can’t explain them all, but feel free to ask if some are cryptic!