EVE New Citizens Q&A

Any.

There is nothing in this game requiring you to have more than one account.

You can accomplish all tasks through cooperation with other players.

If you want to play alone, all the time... you will find your Eve experience very difficult, even with numerous alts.

While alts can make certain things easier (like if you mine you can have an Orca alt as an example), and you can specialize a bit easier (one account can train for all the PVP stuff, the other can train for industry) there is nothing that prevents you from never creating an alt.

However, it can be handy to have low skilled characters on your account for things like market checks, out of corp hauler in case of war dec and so on. You might loose a couple of weeks of training on your main character, but after a while 2 weeks (or 2 months) really wont seem that long

Seconding what Katie Frost and Oraac Ensor said. It's very possible to play with only one account. You just need to be a bit more clever, have some basic social skills, and be a bit more patient.

I personally only have one account. I play in Faction Warfare and it makes good money for me (if I play smart and manage my assets).
The only difficulties I had was getting friendly with a good group of people and in shipping ships and equipment down into low-sec (because I'm a terrible person and shoot people I'm not supposed to shoot )

The first issue was worked through by joining a random corp, helping the "management," learning from them (some of which I did not necessarily got along with), keeping my cool, and getting referrals.

The second problem was easily fixed by creating a basic hauler alt on my second character slot (NOTE: this does require you to pause your main character's training for a small bit... but it pays off in the long run). Alternatively, I have my friends do it for me and I pay them a small fee.

I play without an alt, no worries they aren't needed.

The more you are involved in WH space, cloaking pilgrimming, siting, the more common alts are;
Anywhere in hi and low, you should get by and grow,
with just one alt,
no problems.

Alts are not "required" to play and enjoy this game:

You don't need an alt to do PvE.... EVER..

Level 1-4, Class 1-3 WH's, and up to mid-range exploration sites are easily accomplished solo.
Level 5 Missions, Class 4-6 WH's, and incursions are group content, which should be run with other people, not Alts.

Solo PvP obviously doesn't "need alts". If you are one of those morons that thinks OGB alt's are necessary for "solo" pvp, go pod your non-upgraded clone!!!

Small gang, Medium Gang, and Large Gang PvP is also group content, which should be run with other people, rather than alts!

Capital ships are designed to need a gang-mate to light a cyno so you can travel. This is where there is a NEED for a second player, but it doesn't have to be an alt.... Things like cyno beacons really help enable you to move about solo (lol blind jumping capitals). Capital ships are rarely ever deployed "solo", other than juicy PvE carriers, so this shouldn't be a big deal!

Frankly, you don't NEED alts to enjoy this game.

Now, you should have friends/corp mates if you ever want to do most PvP, and higher level PvE content.