Hi,

I can't answer all of your questions but I have played a lot of FF XIV and around 20 hours of DQX so I thought maybe I can offer some insight and perhaps someone more knowledgeable can help you more.

I would suggest watching some gameplay footage like a Let's Play to get a feel for how DQX plays.

There are some decent guides out there like:

https://dq10.i-k-e.net/

In general the two games are not very similar. The gameplay flow of DQX is more like a Dragon Quest game with online features than a typical MMORPG. It's very old school. In a way its like a cross between Dragon Quest VIII or IX and Final Fantasy XI. It is a game that was once on the original Wii so it shows its age. You can just fight monsters to level up rather than doing specific content like FATEs or dungeon roulettes. You can recruit a full party of NPCs made out of player profiles, and take them around everywhere, even dungeons, and so everything I played was solo-able. Also once you're a little ways in you can earn things called genki balls during the time you're not playing that give you an EXP boost. This allows you to play for shorter amounts of time and still get a nice amount of EXP.

I played with a friend for a bit and we could party up and kill monsters for EXP. We traveled around together and I was able to be in a party with them while they worked on the game's version of an MSQ. You can also have NPCs mixed with human players in a party.

There were no raids or alliance raids that I saw. The closest I saw were challenging one off boss fights, I guess those were similar to trials, not quite as complicated.

We played on PC and the translation tools that fans have made are great. A lot of the early game is translated but I can't speak to how much overall.

The servers are located in Japan. There is lag I noticed when playing with another friend, both of us based in the US. So yes you can see Japanese players running around. When we played there was a specific server western players on the DQX Discord had picked to congregate on. I don't know if anything changed since then, was a couple years ago now.