The trim should only be for looks, a lot of cars these days have no trim fitted. The seal is between the screen and body, clearly your screen hasn't been bonded in correctly.
I guess it will be down to how loud it sounds to the tester. It shouldn't effect the emissions
7.1 in the MOT testers manual https://www.mot-testing.service.gov.uk/documents/manuals/m4s07000101.htm
I fitted these, they've been on 8 years now. http://www.ebay.co.uk/itm/New-Fits-Nissan-Micra-K11-1-0-Hatch-Kilen-30mm-Front-Rear-Lowering-Springs-Set-/291761360335?hash=item43ee550dcf:g:0sMAAOSwbsBXpuBY
If the Bilstein dampers are the same length as standard dampers you'll be fine. I'm on Kilen lowering springs with standard dampers and feel it works very well.
I'd say just fit 3 things, well 6 if you count all 4 springs, Kilen springs, Frankspeed exhaust manifold and a trumpet in the throttle body with the mesh removed.
hmm 10" from back edge of cam cover as it starts to curve downwards from the top surface to the raised seam on bulkhead, so 11" ish to bulkhead in the centre, 12" where it curves a bit around the servo bulkhead area.
seconded, it's crazy to think that the car with the engine swap will be considerably more to insure than a standard 1.4 car, even though both are in effect identical.
oh heck. for a minute I thought you might be feeling left out by all these damaged engine photos on Facebook
https://www.facebook.com/groups/1678600085743105/permalink/1866314600304985/
and independent rear-suspension and an engine tucked nicely behind the front axle line, an interesting and appealing combination that sadly isn't catered for unless you make your own :)