I am really torn between the 2. For enchanting, I am just thinking of stealth run to dungeon boss, kill boss, loot blue gear/disenchant for profit. But I am not sure which boss are soloable as a rogue and if the blue disenchant reagents below large brilliant are even worth it…
There will always be competitive players who push their own/raid DPS to the limit, do speedruns etc. There will always be casuals guilds who carry too many so the carriers need consumables.
Alchemy will always be good, OP. Transmutes are a passive income. Flasks and potions will always be in demand (but keep in mind that the supply is also high).
Rogue isn’t such a good boss-solo class. But your disenchant plan can still work - worst case you can solofarm Small Radiant Shards and make some bank on Minor Speed enchants. Further, there’re not many enchanters usually, so you may get some rare raid patterns for which people tip well.