Is it okay to keep all my characters to always have their maximum level?

I’m kind of a newbie here.

Is it okay to keep all my characters to always have their maximum level following to the increasing team level ?

Until now it has seemed okay, but I just worry aboit how if later I would suffer from any kind of shortage for level-up materials… etc.

Depends on how much you care about PvP. If not, go for it and level them up, as long as you have enough xp. If you care for it, only level them as much as you can follow up with the skills, since you will get punished for underleveling them.

Thanks for your reply.

This is my another question. Is there anything else except the PVP to enjoy in this game in the long run?

I’m not saying sarcastic, but asking it seriously.

For example, the scenario mode doesn’t seem endless, so now I guess anyway the PVP mode must be the only one ultimate content in this game.

Am I having a wrong idea about this game …??

Depends on what you like. For me a long time motivation is to level up all my heroes as far as possible. And the story mode is not endless, but new content is added every now and then and to finish sector 13 on hard is pretty hard, even if you have a good team.
In a competitive way PvP is the main content. But there also is the bounty event every second weekend and the upcoming alliance wars.

I think you should keep your skill levels consistent with hero levels, even if you don’t care much for PVP. I don’t like PVP in this game that much, but I think it’s important in order to grab hero fragments from the store, and it can be another source of Heronium once you get them to 10 stars.