Love your drawings. Don't think you need worry about compatibility, as others have said.
Quick tip about designing yourlayout. A Hornby point is 166mm long. So a crossover, as you have at each end of your loop, is about 330m, 660mm for the two. From the 1200mm total you've allowed, that leaves 540mm to play with, for the loop body and for the bits beyond each end of the loop.
How do you use it? If you allowed 300 mm for the loop body, it would just take a couple of 57' coaches or around 6 wagons, leaving 240mm. Allow 150 on right for loco run around and buffer, catering for tanks and small 0--6-0s, leaving 90mm for the other end, not a lot. However, if you allowed for shorter coaches or 4 wagons in the loop you could reduce it to 200mm, and had only tank engines so reducing the right hand end to say 125mm, that would give you an extra 125mm for the left hand end, or 215mm total.