how do you level up?

[wolfwingtube]

i know it's over time, but if I want to say try another char half way through the campaign does he get it from completling earlier missions or what would I do to get him higher level? *though he would benefit from gear we've found*

[Sigma]

Each character has their own progression sheet, check the last tab for each character. Some missions give you stats/skills/feats and whatever. All you simply have to do is complete missions for those characters and they are rewarded for whatever the mission gives to them. You will need to do this for each new character you create.
And yes you can give new characters overpowered weapons from adventure 6 to use on adventure 1. There's nothing stopping you from doing it. Similarly you can take your properly leveled characters to complete missions, essentially "carrying" the team to raise your newly created characters.

Although it feels more interesting to play with a newly created team of characters than to add in an existing properly leveled up character, it's up to you how you want to play.

[wolfwingtube]

can I just do easy missions over and over, or do I have to complete the missions with rewards for leveling or all quests I've done to get a old char to current level?

[Sigma]

Look at what the missions give you. Each one gives you a specific kind of reward. Not all give stats/feats/skills. You do not have to do them in order at all, you can also do them on easy mode if you wanted.