If you level and just use two or three skills, then you will get to end game with a useless character.

You need to level all skills in your classes to at least Morph Stage. Don't have to take the morphs unless you want to. Same with your primary and secondary weapons. You also want your passives fully skilled, that is where your character power really comes from.

While leveling you should be preparing your self for the future, not your build (as that will change). So:

1. While leveling, have one class skill from each class on your bars at all times. Classes level the slowest, so get them done now.
2. Have at least one weapon skill on your bar at all times
3. Have a flex or support skill you want to level at all times
4. Once the skill gets to the Morph stage, then put another one on the bar to level that rather than take the morph.

Your not going to have the best DPS now, but you will have the most flexibility later. You can apply this to both bars equally or some other way, but this is the best method while leveling 1 to 50. Reason, the game handicaps you right now to make you stronger than you really are. So, take advantage of that. You don't need the optimal skill load out, you need the optimal leveling load out.

Also, try to wear at least one of each weight of armor to get all those lines leveled.

Once you get up to or near 50, you should have all the skills that matter at Morph stage, your armors at 50 and most important, your classes at 50. Then, you can optimize your build.

Wow - I had a lot wrong. Thank you so much all.