Can you skip the first ten RCM grades?

You can go straight in to whatever grade you think you can complete. Doing lower grades is a good experience for being aware of what actually happens in an exam situation, and also to show expectations of playing levels, etc.

Higher grade exams require a lot of work, and the playing level will need to be a lot more than just 'good' to attain a good score. There are also other considerations - aural tests, scales, arpeggios, sight reading come to mind, all or none of which necessarily will be easy for you as merely 'a player'. It also costs a fair bit of money to enter - even lower grades aren't cheap. So why would you gamble all that money - which is effectively what you may be doing.

Don't know at all about that exam board, but ABRSM for one requires grade V theory to be passed before taking grade VI and above practical. Not all exam boards">boards have this inbuilt.