Nice MSP, looks clean!
The major weak point in these engines is the pencil thin connecting rods. Crankshaft is forged and strong.
You are correct about the oil system. Here's a thread about it and what a lot of people did (including myself) to remedy the issue.
https://www.mazdas247.com/forum/index.php?threads/fs-de-oil-system.123700949/
There is another company offering a high performance oil pump. Looks like it would work well.
https://www.boundarypumps.com/mazda-protege/stage-ii-mazda-protege-fs-fp-high-flow-billet-oil-pump
I'll do my best to list everything needed to "do it right"
8.5:1 comp pistons. Wiseco, CP or Arias (higher comp can be used if running E85)
Pauter, Molnar or K1 rods
ARP main and head studs
Main, thrust and rod bearings
Oil pump (docb or boundary)
Fel-pro or Cometic head gasket
Oem oil squirters, frost plugs, oil gallery plugs, full engine rebuild gasket set, spark plugs
Gates Racing timing belt plus new water pump, idler and tensioner
Adjustable cam gears
All these parts are no good without the proper prep and machine work to the cylinder head and block. Services you'll require to ensure a stout engine that will last for many miles:
Clean, inspect/mag flux block and crank to ensure no micro cracks.
Re-surface cylinder head, valve job, new seals and set valve clearances to oem spec. (you can port, polish and completely trick out the cylinder head with supertech goodies but it will cost a lot)
Block bored using a torque plate and ARP studs (BHJ makes one for the FSDE and I believe it can be rented). Do some research on boring high performance engines and you'll see why this is such a crucial step.
Re-surface block deck. It's important that the machinist removes the correct amount of material from the deck so that the clearance between the piston crown and cylinder head is 0.040". This clearance is determined by measuring piston to deck distance and the adding the thickness of the head gasket being used. (ex. piston to deck = 0.010" + 0.030" thick headgasket = 0.040" piston to head clearance).
Line hone the main bearing caps using ARP studs.
Balance rotating assembly (pistons, rods, crank)
Ensure all main and rod bearing oil clearances are within spec. Piston ring gaps need to be set as well.
If you need the factory engine rebuild manual, it is available for download so you can reference all the clearance specs, torque values and procedures.
link