Can understand your concerns. Starter - now turning an engine with more compression? Air Con compressor - a) pulled around in the engine swap; b) was it working B4? Seems excessive to swap out and regas. Washer tank could have been moved roughly or hit during the transplant. Lots of rasons for DIY (if possible for you) here. Bit too far for me to drive from Perth to help you......
Good - Fast - Cheap: Pick any two.
E23 735i; E30 318i; E32 735iL (X 2 - 1 White and 1 Light Blue); E34 535i; E38 735iL; R50 Cooper; R55 Cooper Clubman.
E21 318i; E32 735iL; E34 535i; E38 730iL; E53 4.4i