For the lack of kick, are you sure it's a boost leak?
If it were leaking, it'd be chewing through the fuel.
Your VCT may have become disabled some how (Bad electrics/plug off)
My car at the moment, doesn't have VCT turning on until 2250 RPM, and you can really, REALLY feel it kick in, and when you watch the boost guage, as it kicks in, boost climbs dramatically (When cruising, it'll sit at atmospheric, as soon as the VCT closes it'll jump to 2 - 3PSi or there abouts.