That is an impressive spec - my advice, same as given to a mint WR1 owner, have a price in mind that you will be happy parting with it and stick to it, may take some time but the right person will come along.
bit of 'T' cut will sort that out :D
great to hear you are all ok - and big congrats to your missus I know she will have had to put in some serious graft to get that under her belt
sounds like a cog has dislodged or broken a tooth or two internally - the buzzing is either the motor trying to move and cannot because stuck or the motor moving and rattling against the broken cog
when it comes to the exhaust PPP options tend only to be the backbox so getting a full milltek system will reap more results (with filter, map and uprated fuel pump)
form an insurance persepctive dealer fitted PPP options tend to be more friendly giving wider options but if you shop around there are more people now willing to offer insurance to modded cars at a reasonable cost
As above - engine swop or sell / exchange for turbo model, simplist way. With the mileage yours has done bolting on a turbo charger without a full rebuild would not be wise so better to go for the simple options
you'll get the hang of it - its the same principle as the primera but all arranged top to bottom instead of side to side - oh and a bit of turbo piping