ADB25,
as a low hour microlight pilot, my opinion is really not more than 0,02 euro's, for that worth here goes:
-) your struggle is at the hardest point to be conquered, so it seems quite a natural thing;
-) I agree with others you should get a maximum out of the instructor, you're paying quite a lot of money and you really are entitled to a maximum of return for it;
-) OTOH I also agree with the earlier word that the best possible feedback your instructor could give you is to sit back relaxed - you can't be doing that bad!
-) you didn't specify what plane your are training in (or did I miss that?) but, though you should indeed be looking outside as much as you can ever manage, in certain type you do want to keep half an eye on the ASI. I trained on a variety of high-winged Rotax 80 hp-powered LSA's, and the one thing they had in common was an optimal approach speed of 110 km/h. The more performant the plane, the stricter this had to be respected.
-) as for what to aim for, normally it is "the numbers", or so I learned; but they are not present at all runways. On one very performant microlight I briefly flew, the secret was to aim 300 ft short of the threshold, and be happy to touch down 300 ft after it...
Good luck, happy flying, and always keep to the safe side of pleasure!