Felix
I suggest a dynamic approach to your game plan. On paper it looks like a very reasonable, progressive route and writing it out like you have is a useful tool. I am not as far into the training as others here, however I think it very good advice to allow the sort of margins suggested.
Be prepared to adjust your game plan, you have a goal and its a good start to pencil out a route, just don't be too tunnel visioned at any stage.
I also think its a good idea once you have got your "rough route" to focus on the present time hurdle, and drill down even further within that. Eg have a goal in mind (if its big metal thats your motivation then by all means have pictures of the stuff around you), but for example, when doing the PPL exams just concentrate on one at a time rather than thinking how the ATPL's will compare.
On the money front with regard to the offer from your parents, and this is just my opinon, but use it for the latter stages ie Multi/IR, MCC. I think it prudent to use your own wages/savings to pay for your Medical, then PPL, then ground school, then hour building and only after all those bits are under the belt would I use any loan from either family or banks. You will have proved to yourself and your folks that you can manage your money, you will have already realised your own potential and have a more realistic idea of costs as you will have encountered the "extras" that everyone is talking about.
All the best
Camel Toe
"Over Macho Grande?"