I was just wondering.....
1.) yes you can. gift items are account-bound so you can do them on alts. Take note that the bloodstone shard (200 skill points) and the other stuff you buy from miyani (the crystals/stones for mystic clover making) are soul-bound.
2.) You can, so long as the rarity is the same (all 4 rares, all 4 green, etc). However, by doing the bow, bow, bow, bow route, you are guaranteed a bow outcome. Diff random stuff will give you random stuff. Imo, it’s generally an item/money sink, and unless you’re doing it for getting exotics/precursors, you’re better off salvaging them for ecto or selling them on TP.
That’s for the random aspect. the MF also has a bunch of set recipes you can take a look at at http://wiki.guildwars2.com/wiki/Mystic_Forge, or more detailed here http://wiki.guildwars2.com/wiki/Mystic_Forge/Other_Items
You can always switch crafting, you don`t unlearn them per se, you can re pick it up again whenever you want, it costs 40S for a max`d profession to retake it & you`ve everything you learnt before.
https://forum-en.gw2archive.eu/forum/game/suggestions/Top-right-GO-away/first#post2096524
Rocking Wizard Wars until this mess of a game is fixed…