No its not just you, I can't H&T to save me on LFS, even though I can preach about it all day and demonstrate it in my car on the road and track.
On LFS it turns into random stabbing of pedals, usually sailing past the first corner into the barrier. This is even though its exactly the same theory and layout as a car. Go figure.
I've consigned the G25 gear lever to the loft, I prefer to use the paddles behind the wheel and my left foot is constantly covering the brake pedal.
As for your pedals on the same axis - go to the controller properties (under Control Panel > Game Controllers) and you'll see something along the lines of "Use combined axis", it is likely ticked.