1. I highly recommend a boost controller. It is money well spent. My AVC-R is nice, but there are better ones out there from what I have seen.
2. This is always hard to diagnose without a leak test. I have the Boostpro kit with the compressor adaptor and it works very well. A lot of TTs make strange hiss and whine noises from what I have seen, no two sound exactly the same. Some were fine and some were very leaky. Suffice to say a boost/vacuum leak almost always causes drivability problems. Sounds like condensation also and/or rich start that TTs have until warm.