Good advice from TerryQ & Steve Neul.
It's taken me a while to accept that biscuits serve only to help with alignment, and don't really add any strength. I suspect that with today's glues, the same holds true for dowels.
I've found that using biscuits for a multi-board glue-up can be tricky, and puts pressure on me to work quickly. I don't deal with "quickly" & "pressure" as well as I did when I was younger.
Most recently, I glued up 4 boards to make a lid for a blanket chest & used biscuits in the joints. I guess the buiscuits swell up with the glue, and I didn't have as much time as I thought to get everything clamped up. A good whack on the edge of the outer pieces was required to get the joints to completely close up. I used Titebond III Ultimate, FWIW, which should have an adequate working time.
I'm about to glue up several boards for a table top for our new kitchen table, and will not use biscuits. I plan to use crosswise pieces (cauls?) loosely clamped in place to hold the boards in alignment. I'll make an exception if any of the boards are bowed & need a bicuit to enforce alignment. I think this will give me the time I need to ensure that the pieces are lined up, the top is close to square, etc.
Regarding the OP's concerns about butt joints with some of the pieces, I'd suggest a clamp on the length of those pieces before fully tightening the crosswise clamps, to ensure that the butt joints close up well.
And on a general note, especially with a project such as this, you can never have too many clamps!