Interesting on the tube selection. I don't have a Premier Widow but as Allen says, the P200 is a pretty tuff tube and should be ok as a LE or LS in winds up to 15mph. A P300 spine, P200 LE, and 5PT or P200 LS is pretty common framing for a std.
The heavier tubes are great for adding momentum to tricks but will contribute to oversteer as will lots of tail weight.
Balance and stiffness are other factors to consider when selecting framing. Lot's of trial and error here.
I know the Widow Maker is framed in SS Nitro tubes which weigh the same as P200s but are stiffer.
To summarize this thread, try moving the bridle up and out a little, reduce tail weight, and reduce weight at the extremities to tame the oversteer.
Don't forget that technique may
help compensate for oversteer as well.