Paying off that bastard loan is tough. I hate debt too ... but I do fully get your longing to get gone. But settle down and think it through ...

Is £5000 enough for your proposed UK to Magadan trip?
Why not take a month or two and ride out there? Maybe sell off the bike at trips end if you can get a good price? Fly or Bus it home. Just a thought.

I have no idea how you could walk away from your job and then expect to be re-hired after a year ... by anyone. Time gaps in your resume don't look good to potential employers.

34 years of age? Oh my God! The End Is Near!
All washed up eh! That is funny!

Seriously, I'd guess you've got maybe 30 years of work in you yet? .. and hopefully even more years of bike travel as well. Stay healthy and fit ... you just might make it! (remember that old grumdgeon Gandolphi?)

Like others have said ... the travel bug you've got now probably won't go away. Can be a life long affliction for some. For now, I'd focus on career and getting very good at what you do, become established to the point where your boss figures the operation can't go on without you. Until that time ... you're expendable and you could be ... here today ... gone tomorrow.

It would be nice to be able to get a month or more off and do some shorter trips ... but some jobs don't allow that. A shorter trip is better than none and may not require "cashing in all your chips".

Best keep your nose to the grindstone until a "natural" break comes along and gives you the time to travel ... and hopefully you'll have saved enough money as well, so no debilitating loans and no walking away from a decent job.

I wouldn't do a RTW now. I've seem most of the world and have strong feelings about places that are worth re-visiting and places I'm not fond of. Don't waste time traveling in places you'll not enjoy. Focus on areas you do enjoy and go there. You can see and do a lot in a month. Well planned month or two rides can be great and you may not have to "cut all ties" in order to do them.