Hi and welcome to SWCF!
There's no reason at all why you shouldn't learn watch servicing the way you're hoping. It's not as easy as having someone experienced to point you along the way, but it's certainly possible.
As well as following the tutorial, it's well worth picking up some basic manual wind Swiss stuff off EBay - try to make sure they're basically running because fault finding tends to complicate things quite a lot until you gain some experience. Also stick to "known" makes (Limit, Accurist, Rotary are all good) because some of the unknowns are such poor quality that even seasoned pros will be tearing their hair out trying to work on them
If you go for stuff with poor cases or dials you can pick them up for peanuts, like this sort of thing:http://www.ebay.co.uk/itm/Mens-vintage-Limit-watch-gold-case-expandable-strap-working-spares-repair-/330849599847?pt=UK_Jewelery_Watches_Watches_MensWatches_GL&hash=item4d082c4167
Use them as practice pieces - note how they're running when they arrive (rought timekeeping check and how long they run on a wind) then pull them apart (the basic techniques are exactly like the tutorial teaches - just less parts involved), clean them, reassemble and oil and see what difference it's made. Then pull them apart again until you can do that sort of movement without thinking. Years ago, I used to bet a few friends that I could strip and reassemble things like that after an eveing in the pub
Once you're completely happy with basic mech stuff* automatics and calendars become a lot easier because the basic movement is pretty much the same in most of them. So you only have to "worry" about the auto work and date mechanisms. The ultimate aim is to be able to strip and assemble any
watch, without the manual, and have it running afterwards. The manual is useful for complications, and always advisable for things like correct lubrication / any adjustments involved, but it's entirely possible to reach the stage where the basic stripping and assembly is done using common sense and methodical working.
Your 4 year plan should give you a fair shot at getting to that stage if you find yourself taking to it
*years ago, I used to bet friends that I could strip and reassemble things like that after an evening in the pub. Even did one in
the pub once