As said, this is all from someone who can't script or build worth lima beans. So, take this with some caution, because I'm offering info without being on the inside of a process. Here's some thing's in general I've noticed that make it easier on players, and keep the player base active and happy.
I've seen more than one server tank hard because the builders lost sight of what the server needed more than a lack of bugs: players. When a server opens, it's got to have some support system for new players exploring the world and it should be explicitly and implicitly understood by build teams that these players are 95% of the time going to be on their own. "Not SOLOING!" Yeah, soloing. Unless you have 24/7 DM coverage and ideas to throw at players 24/7, the average time online in the early days for any given player are going to be *brief*. The idea is making an environment that keeps the time online and the frequency of visits as high as possible. As more people are 'lured in', they will begin to interact and spend less and less time soloing. Make the server solo friendly for the early stages of whatever level range you have on your server. Players stay online when they see progress (that's not "start at level 5", it means doing quests or easy combat), and you can always make it harder later on after they've had time to mingle.
Bugs matter when a player complains. It's that easy. If you want to get the 'important' ones first, ask the players for feedback.
Similarly, your RP background only matters as far as it helps the players play. Epic backstory is great...when it gets used. Most of the time, it doesn't. And just explaining why something- like a god, or a tower, or any other standing fixture- exists, that's not being 'used'- not unless the players are planning and interacting with the fact in a dynamic fashion. For example, giving a short novella as to where and why your unique pantheon of gods came from is nice- for you. The players- even good ones- are moving straight to the deity list and choosing their cleric's gods based on alignment, portfolio, and *how their clergy fits into the game world*. Unless that huge backstory somehow changes what the player can do, can't do, who likes or dislikes them, and what they might know or not know RP-wise- it's wasted effort. You don't need to be Homer or even Edith Hamilton, OK?

Having a higher-end machine myself, I haven't even thought about area size in terms of load time or computer speeds (but that does matter). What I have noticed is useless space. A location- or an area- is defined by the things within it that players can interact with. Using that axiom, you don't need 10 massive areas with 6 things a piece in them for your capital city. (This happens alot.) The players are simply going to be annoyed with all the time it takes to get from here to there. A capital city for example, should be a place where it's cosmopolitan: there's more STUFF there that you couldn't get in a small village. You might have 4 different smithies and 2 playhouses and even an arcane academy- the idea is to 1. Make the area big enough(not more) to encompass all those cool things and 2. Have enough areas to fit them all in with plausibility. (The dockmaster or ferry men need a water front obviously- so go ahead and map an extra area. Does it need to be HUGE? Well, if it's just for those one or two things, then "No." Make it tiny. The players get the idea.) Don't inflate areas in a quest to impress. Make it so the
content makes it bulge with activities for the playerbase. Conversely, don't be afraid to make services or items simply unavailable somewhere. Not every village has a scroll shop.

In-module barriers to players based on level and/or prowess are always appreciated. Nobody wants to 'accidently' walk inot that liar of the 1,001 Rakashas as level 6. Most servers are very good about this, but don't be afraid to have an NPC simply say "No, I don't think you've got enough experience yet for something this tough, and I don't want your life on my conscience." (or whatever works).
Make sure nobody dies for stupid reasons. These are the one type of bugs to ferret out before the players bitch and moan. Example of a stupid reason: The guard has a "put the weapon away- do it now- *attacks your ass*" script in place. OK, that's not so bad. Maybe even ideal. Here's where it gets stupid: The server's "Holy Symbols" are daggers with like -5 damage. A cleric wants to turn undead or display the holy symbol- which is not a crime(usually) or even a 'weapon' really. But it activates the guards' script- and dead 1-st level clerics litter the streets on a regular basis. (Or conversely, dead GUARDS litter the streets from the divine wrath of the 20th level clerics they attacked).
That's stupid, and players leave over things like that when builders just go "oh well".
Anyway, I've got more ideas, but I'll save it. Just don't forget the server is for fun and players- it's not a resume for your next programming job.

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