Quote Originally Posted by Mirai View Post
I think in general, I'm just looking for ways to progress, doesn't even have to be with my main team. I know this game is a marathon so it'd be good to know what the long-term goals are
Really depends on how much time you're willing to invest into the game and whether you can find active friends and union to raid with (leech from.) I personally think most new and returning players should focus on farming guardian weapons to at least get rid of all the SR weapons in their main grid first, but that may be too much grind for some already. Getting accessory slots unlocked is also important (and just as grindy.)

I am going to answer your specific questions with the assumption that you are willing to grind at least several raids a day on top of regular events:

Is my understanding that with the release of Leviathan (and hopefully getting her eventually), I should keep an eye out for water eidolons and max them out even if they don't have the highest stat?
Generally yes. For Cerberus, Leviathan, Hanuman, Nidhoggr, you get an 8% additional elemental per matching sub eido (Managarmr (fluffy) and Anubis also work similarly, but theirs is 4%-8% per matching sub eido depending on LB.) However, that does not mean you should stuff R and SR as sub eidos (I've seen this more than once) - the stats loss from using non-SSR can outweigh that 8%, since your Rudra plus a friend LB0 Leviathan and Herc axe already gets you to 230% elemental (3.3x multiplier) so the 8% only gives you an incremental 2.4% dmg. If you lose more than 2.4% in stats from swapping to R/SR, you would actually end up dealing less dmg.

Do I just need to wait for water event SSR weapons as they come?
You can try to farm guardian weapons (Ophiel for water.) Ophiel axe and lance are both very good end-game level weapons. Note however that Ophiel is one of the harder guardians and has a fairly high fail rate.

For all other teams, I have 1-2 SSR himes, but just slapped on off-element beat sticks for weapons (like the FLB rahab knife).
That's probably not a good idea. Even relative to a disaster SR, the loss in assault typically outweighs the gain in stats unless you're like completely new with no stats (that should no longer be an issue for ppl, as epic quests basically gives you a basic set of eido statsticks to start with.)

Is it worth getting all the raid SR's and maxing out the skill level for my other elements?
It's probably worth getting a basic SR grid for thunder at least, as the next tower is in roughly a month and is water, so thunder has advantage. SR thunder axe grid might actually outperform your water grid in a water raid depending on who you have as well.

My next question is with accessories. I don't have the 4th and 5th slot unlocked, so I think that's definitely something I need to work (ragnarok raids I think?). Do I want to eventually go for the Tiara set bonus?
Slashley answered this already.

Are there any accessories worth getting the the Accessory Point shop?
Not really, they're all fodder pretty much. If you're not doing AQ4+ yet though, I guess you could buy the ancient or devil rings to see if you get a nice one (more often than not, it'll be a bad one, but might still be better than the really bad ones you typically see.)

Raids - The guardian raids are new for me and it seems like they have treasure drops that let us exchange them for weapons/guardian eidolon at shop. Are any of the SSR weapons or the eidolon worth it? Or in general, what should I be spending these treasures on?
There's usually at least one really good weapon for each element that is worth farming (fire is the only exception, where they range from bad to usable, no great ones.)

The guardian eidos are also good for any element where you do not have a 100%+ eidolon, or if you want to run a high utility team (or if you're running a high vigor grid.) The way they work is that they scale up the weapon skills from your grid, so their strength is proportional to the quality of your grid - well worth using for well-built grids, but can actually be worse than an event eido when you're still running mostly SR weapons. It's a fairly long grind to get the guardian eidos MLB though, especially since you missed all the rush phases already.

Quote Originally Posted by Slashley View Post
So uh, again... just keep playing and try to enjoy yourself. That is, after all, the end goal - having fun.
Just remember this.