When I land on FS I never use the ILS but I am completely dependent on the headings from ATC.
BUT they are always incorrect I get to the airport alright but never do I land in line and I am always off the runway completely.
Can someone help with this other than suggesting ILS.
ATC doesn't put you on the runway, they give you vectors to the ILS approach.
My suggestion is a smaller airplane, and practice with a high head wind, it slows everything down and you have time to correct for mistakes.
try making very small adjustments once you have adjusted your glidepath. It appears that your problem is not an altitude one but for left to right problem. Unless you're in a crosswind, keep your wing level and make only small adjustments. In a crosswind, use a crabbing technique, side, or forward slip, to align yourself with the centerline. As it was said above, the atc only vectors you to the runway out of your cruise. It is your job to land the plane and fly the localizer to the rwy.
You did not menton that you were having problems with your display responding. What you described is a simular problem that I was experincing before I got a hold of a system the would give me a resonable frame rate. Without a frame rate of 20 I would be correcting but did not get the visual feedback so would over correct then need to recover with the feedback trailing I would be chasing the movemnt.
If you frame rates are good please forgive this tangent. With my frame rate inprovement I mostly put in on the runway maybe not always centered and only sometimes into it. 🙂