Hello
I have no idea why you would suggest rosa, as its liquid wax super filler and has nothing to do with removing defects from paint.
The Meguiars microfibre system is an excellent product. But after extensive testing it cuts alot faster then most compounds on a rotary. So to a hobbyist I wouldnt recommend it just in case. There are meny compounds, polishes, fillers and pads on the market, so it's what you find works best for you. My personal opinion is to go with a tester kit that is bang up to date. This way you will have compound and polihes to suit 90% of the tasks in hand. If you want my opinion on compounds and polishes, then go for scholl concepts. They are at the height of modern compounds and polishes. Very easy to work with, very low dusting minimal silicone fillers. Mix these up with there pads and you will get great results. Below is a link to the 3 main ones you will use over time in testers.
Scholl Concepts Polish Sample Kit 250g - Elite Car Care
These are great as you could do between 3-5 cars with these so plenty to play with. Here are the links to the pads to get.
Compounding/slightly aggressive polishing, without the use of wool/sandwich pads:
Scholl Concepts Orange Polishing Pad 145mm - Elite Car Care
This pad can be used for compounding too but is a little softer so great with the medium cut polishes.
Scholl Concepts Orange Polishing Pad 145mm - Elite Car Care
This pad is great for your refining to give the car that super wet glossy finish after the machine polishing stage.
Scholl Concepts A15 One-Step Allround Medium Cut Polish 250g - Elite Car Care
So a small re cap:
For compounding use the orange pad with s3 gold edition.
For polishing use the blue pad with s17.
For refining use the black waffle pad with the s40.
But with all modern products of this nature you can mix it up. The s3 can be used with the blue pad and the s17 can be used with all 3 pads etc...
Hope that helps.
Mike