Fitting things into an A2000

[Amiga4k]

Answers:
(1) The GVP Combo card will slide down with the "plastic card guide" in place. Remove the GVP card. Replace the plastic guide. Insert the GVP card tilted down at the rear. After the external SCSI connector is into the rear slot, apply slight pressure on the top front edge of the card. Gradually press and get the card level and into the CPU slots. The rear screw holes do line-up on the card and A2000 case.
(2) Either use a 5.25 to 3.5 adapter tray and mount the drive under the floppy bays (the 5.25 bay slot). Or, buy blank edge card (no traces, just a virgin blank) to fit into a Zorro-II slot. You'll have to size the card, and drill screw holes.
Or, you could use an old A2091 card just for the mounts and power. (Not using the SCSI connector on the A2091).
(3) Consider that question answered. It is awkward.

[Amiga4k]

Caution note:
Using a veroboard is an excellent idea, but just remember:
(1) the loss of either 1 or 2 zorro-II slots depending on how you set the card and drive.
(2)after connecting the SCSI cable to the processor card besure to use duct-tape to pad the ribbon cable on both sides. The processor card and the A2000 case are going to pinch the ribbon cable.