Stand alone they will do nothing with the current engine setup. they aren't super restrictive.Once you start opening up the intake system such as better intercooler then you will see the benefits of doing the charge pipes.
Faster sound as the speed increases makes me think it is coming from a rotational part. Since you were working on the driver side and removed the air box, I would check to make sure nothing is rubbing on the axle maybe?
It's not but as an owner of the PRL Cobra myself it is such a wonderfully built piece that I wouldn't get anything else. Be careful of false performance numbers and some name brands just didn't do the research like the others did just so they could get the product out there quickly. The Cobra...
#1 could be a spring binding in the suspension. Mine makes it on the passenger side and I just haven't really checked it out. I had it on a previous car when the bearings went on the mount, the spring can't move freely with the turning of the wheel.
Tire's are always your number one game changer in handling. If you put the same size wheel and type of tire on the two I would think that is when you would get a fair assessment of the difference.
How many miles on the car? I have ran into the same issue but it seems to (knock on wood) have gone away other than when going into reverse as I have put miles on the new Type R lever I installed. The SI lever seemed to figure itself out after about 4K miles on the car and eliminated any issues...
You could try taking the center console apart and driving around a bit with it safely and I mean safely partially put back together but with the coverings around the gear lever off. This would allow you to see what is going on when it sticks.
The part was repaired about 2 months ago and the gap is still gone on one side but has crept back on the passenger side, although not anywhere as bad as it originally was.
Same day because they just remove the wipers and then just replace the cowl. Pretty simple. Had it done at the same time as getting my oil changed and the gap was just like the OP's was but on both sides.