Re: casting weight
The "3 - 4" number may be the issue here, go to a weighted fly and only one, but wiser minds than mine will chime in on that. As for the bobber/indicator, go to a smaller size or use what (for a lack of a better term) the guys here on the Rogue do which is a 'flop cast.' Looks ugly, but watched guys toss indicators the size of a golf ball with a 7wt road.
And before I forget, welcome to the NA version of the UK fly fishing forum. Any predictions on what your snow pack may be like this winter?
"We sleep soundly in our beds because rough men stand ready in the night to visit violence on those who would do us harm." – Winston Churchill