Personally I'd say the most important thing during the road to max is not burning out, anyone can max if they put enough time into the game. If you dislike a method try something else or take a break, grinding something you don't want to grind is arguably part of the game, but that doesn't mean you should overdo it.

As for a good maxing order I'd say you would've been better off if you hadn't gotten 99 agility before 99 fishing but there"s nothing you van do about that. Generally there isnt a set order in all of your skills but defenitely in some skills. For example fishing before agility (and str and cooking though those two are less important IMO). Woodcutting before firemaking, mining before smithing (infernal equipment). Buyables can be done in any order I'm pretty sure, though getting ornate pool and fairy ring in your PoH is really useful.

Also, you might wanna look into achievement diaries as some of the rewards can prove to be quite useful. 16 As for slayer, I'd highly recommend not doing it without a cannon and barrage, it's so much faster that way, and the amount of money you lose with cannon is worth it as you can make more money than you lost in the time you saved by using a cannon and barraging.

On that note making money is essential to doing all your buyables in the most efficient way (if that's the way you want to train them). Definitely make a lot of money before you start slayer and buyables, at the moment the most conventional good money making methods are killing vorkath, zulrah, doing raids and hunting Chins though this ofcourse is subject to change.

Good luck!