If you think that every single thing you mentioned in your post is an exploit cer then you are wrong. Several of our old toys were intentionally put in this game and got removed when looms were introduced and made them not needed anymore like the leg armors and so on. Blizzard told them selves that some enchantments were for faster leveling. That we used those in pvp was just a side effect.
Original leg enchantments were designed for endgame, not for low level twinks. Exploit.
Shoulder enchantments were for level 60+ depending on the enchantment. If you put it on BoA Shoulders, lower levels could use it. Exploit.
Original Helm Enchantments were designed for endgame, not for low level twinks. Exploit.
WBFH is not an exploit. However they were never supposed to be released with a 0 at the end of the 4. (+40 to stam/spi). Blizzard's mistake, we took advantage of it. Not technically an exploit so you are right there.
Buffs for your level should only be available for your level. At level 1, a higher level could give you kings. A level 1 shouldn't be able to have kings because you couldn't get that buff until a higher level. Exploit.
Mining @225 was glitched. Instead of giving 7 stam(70 hp) it actually gave 70 stam(700 hp). Exploit.
Professions could be maxed higher than your zone's level range. Therefore receiving that profession's buffs that were designed for higher levels, but received at a lower level. Exploit.
Fish Feast had a level 70 requirement to make. However even though it was designed for levels endgame @80 but could be made at level 70+, ppl could get this buff at lower levels such at 19 but cannot create the feast, just benefit from it. Exploit.
Titanium Weapon Chain can be applied to a BoA Weapon a lower levels get still use this enchantment even though it says it requires level 70+ to use. Exploit.
Glitching under Gurubashi Arena and being right under the AGM Chest and grab it unchallenged and without being seen. Exploit.
As long as your BS was at 1, you could get a gem socket in your gloves/wrists from dungeon gear at lower levels even though your BS needs to technically be at 450+ to get this. This is applied to Engineering too. Exploit.
And of course Terrain Jumps(exploits). Terrain that is glitched so that there's only a small part of a sliding hill that you can jump on top of in order to get to an unreachable spot in order be difficult to catch or get to. Exploit.
Looks like you were right, not all of them were exploits. Just that 1 I mentioned.