Yeah definitely bigger injectors in there with that turbo.
As mentioned you need to get the brake discs machined. Front ones more likely but do you feel the shudder through the car or through the steering wheel and car?
You may have a broken gearbox or engine mount. Get that checked out.
Yes it's a big turbo so it will be laggy. You can take the cam gear covers off and check if you have adjustable cam gears in there. If you do you can use them with a retune to bring boost on earlier, if not you can have them installed.
You sound like a sensible guy so I wont harp on the be careful comments but one thing I would suggest is that you do a skid pan day of some sort. The club will be holding another Texikhana early in the new year but there are others around fairly regularly.
Also, yes take it to the drags. You might get a high 12 on street tyres. Go a few times with street rubber then consider getting some drag radials for some better times. Post up when you are going and you will probably get a few others coming along so you can meet some like minded and helpful people. We're all pretty much here to help each other out.
Lastly, you will need to find a workshop that suits you. Whereabouts do you live?