Recommended readings:
...........
Is the game still active?
Yes, concurrent players online at once on a single server range from 1500-2500. There has only been 1 server merge occurrence in the 10+ years the game has been open. Starting cities as well as Whitegate are not very crowded nowadays, due to Jeuno now being the typical place to be (because of Abyssea/etc).
I haven't played/subscribed in years, is my character still there?
As long as you didn't actually delete your character, yes it'll likely still be there. SE rarely ever deletes inactive characters (even though they say they do).
What server should I join? What is the best server?
There is no best server; servers with high population result in overcrowding and there aren't really any low population servers after the server merge. The best thing you can do is find a Linkshell before joining a server, then join a server based on where the Linkshell is.
The game seems empty. Why?
Have you just started? If so, you are most likely in a starting city like Bastok/Windurst/San d'Oria. Because they are starting cities, there is not too much use in them for experienced players. The main hub cities are Jeuno and sometimes Whitegate. If you try the command /sea all you will get the number of players currently online.
Is grinding still as essential to the game as it ever was?
No, typical parties are no more and replaced with Fields/Grounds of Valor alliances (at lower levels) and Abyssea alliances (higher levels). Typical XP gains are now 75k/hour at the least. One could level from 1 to 99 in a matter of weeks (or less), outside of Limit Breaks etc. As with most MMOs, there are still some aspects of grinding in other parts of the game (such as Trial of the Magians).
I heard the level cap changed, what is it now?
The level cap was raised to 99 (thus subjob would be 49), with more Limit Breaks as usual. Most of the LBs are easy until the last one.
Has soloing changed at all?
Yes, it's easier to solo now (in terms of missions & leveling). Fields of Valor make it easier to solo for XP, and a lot of the missions (like the CoP missions) have been uncapped so it is possible to solo them now (being level 99 also helps with that).
What upcoming content is there to look forward to?
There is a lot planned, but the main thing would be a new full-fledged expansion called Seekers of Adoulin (new areas, new jobs, etc). This is important because the last content packs were add-ons and not expansions.
Is the game F2P or will be F2P in the future?
No, and it is unlikely that it will ever be in the near future. The game is still popular and has a solid subscriber base.
I used to play on PS2/360. Can I come back on a different system?
Yes, your account/characters will work on any system (PC/PS2/360). You just need to get the game installation/discs, but it will be activated under your account.
How is x/y/z job now?
This is a tricky and possibly biased question. Jobs have changed (especially with being able to be level 99main/49sub) and the developers are still tweaking jobs. For example, RDM has lost a lot of its usefulness.
Does the game still use PlayOnline?
Yes, but not very much anymore. Billing is now done through SquareEnix's account management website.
Does the game still charge the "once per month" bill cycle instead of 30 day billing (like most MMOs)?
No, SE has fixed that (now that billing is done via a website) and the billing cycle is now the normal 30-day cycle.
I'm missing only a couple expansions/addons, what's the best way to get them?
Buy the Ultimate Collection (Steam, Amazon Digital, etc). The normal price is $20 but it goes on sale for as low as $5. Once you have this, you can add the serial key to your existing account and it will enable every expansion/addon for you.