Thank you so much Simon for your help and for sharing your expertise. I really appreciate it!

All your tips and comments are on point.

The finish is looking gradually heaps better past that first shock of seeing the finish going so white the first time. I will definitely follow your advice.

Diluting 1/10 is something that I've read somewhere and instinctively made sense to me looking at the product I am using.
I tried it yesterday. I just needed the varnish to be a little bit less dense. The way it was it made it difficult to apply evenly without having heavy drops appearing and gathering everywhere.
I used a brush for the first 2x coats, as per tin instructions, but ultimately wasn't happy with it and used a cloth yesterday and I am much happier with the control I have.
All this is 20% experience and 80% guts feeling to be honest, but I am learning a lot and it seems to be working fine.

Thanks again for all the suggestions Simon, you shared a lot useful info!