We have the exact same issues.
#1) We do L sit presses from the floor, with the bar supported on the catch bars between sets. The L sit is the most stable position we've found, and a killer core workout.
The bench is probably fine to sub 100% for OHP for now, or floor bench press is probably fine.
#2) We got the Titan silencer drop pads and they are awesome. I know titan is evil and ripped them off from Pound Pads but those and the Rogue version are more than double the price and weren't available in tbe beginning of the summer.
Barbell Silencer Drop Pads - Weightlifting Drop Pad Set
We are lifting in what used to be our dining room, on cement slab with water lines in it that would be brutally expensive to replace, so a quiet deadlift was a top priority of ours.
Here's a video of my last deadlift for noise reference. You can compare it to the background noise of my husband making dinner and running the air fryer, lol. I can deadlift without waking anyone in the (cheaply built) house up.
crash pads - YouTube
Obviously the issue with the pads is the height difference, so you'll need a platform. We looked at buying a premade platform / low box but they were all kind of expensive.
This 6" stackable box was a contender:
Stackable Wooden Plyometric Boxes
Instead, husband built a rudimentary platform for me. It's 2x4s (you can have home depot cut them to length) stacked in a square, plus a cross beam, with a thick piece of smooth 3/4" 2x4' birch set on top, screwed together with a couple wood screws. We made the supports 44" wide, the max that would fit between the rack supports. We wanted it as wide as possible so we could use a deadlift jack, because it's a PITA to change plates on top of a cushion.
The total height you need is 5.25", which is slightly shorter than the pads to account for the "sink".
Here is a picture of the underside:
PXL_20201216_202053895 | Elle N | Flickr