Several questions from a newbie

[StriderShinryu]

Welcome!
1.) Like it or not, you do kind of have to separate Story and Quest Design a little. The story itself does start out slowly with a lot of world and character building but it does get more engaging and interesting as you reach the end of the ARR section. But the Quest Design itself doesn't really ever change all that much. Eventually they do introduce some different wrinkles and ideas but it's still largely MMO Quest based even into End Walker (the current expansion). Just walking around, fighting the odd monster and talking to people is sort of "The MMO Way."

2.) Difficulty in FF14 often comes way more in the optional side content than in MSQ related content as the MSQ is balanced towards something everyone can enjoy, even those who don't play MMOs (or many games in general). So, yeah, don't really expect the MSQ to ever get particularly difficult unless you're doing group content things on day 1 of release and everyone is literally seeing everything for the very first time.

3.) Auto Attacking is essentially always on as long as you're in range of an enemy that you're actively fighting. Even if you can't see the attacks because of other skills/abilities you're using, you're always considered to be "Auto Attacking" so don't worry about it too much

4.) No. Once you have purchased the game your account can not and will not be reverted to a "Trial" state. On the upside, there are many limitations to a Trial account that you won't have to worry about (like a Gil cap, communication restrictions, party making restrictions, etc.)

5.) Monk is actually considered one of the strongest jobs in the game right now, but the game is tuned such that every job can complete every single bit of content. A "weak" job in FF14 just generally means that it does a handful of % damage less than other jobs in it's basic type. Noticeable if you really pay attention but not a true wall to completing anything. Play what you like. Monk did just receive a rework and some new mechanics though, so many people who say "Monk is bad now" really just mean they don't like "new" Monk and preferred the older version(s). DK does start at level 30 but to unlock it you need to be in the main city of the Heavensward expansion, so it's not just level gated but also MSQ progress gated. DK is also a completely different job/role than Monk as DK is a tank and Monk is a melee DPS.

6.) I can't recall early level Monk specifically but it's likely the skill has a prerequisite like a required stance if you can't use it (since you're saying it's not related to level sync, which would have been my first thought). You may also want to ensure it's not a Monk specific skill and you don't have your Job stone equipped as a Pugilist can't use Monk specific skills. Once you have your job stone, it should ALWAYS be equipped but if you're using a gear set from before you got the stone you'll have to equip the stone and re-register that gear set with the Stone included