If you don't care about what difficulty for SA Hanzo, easy mode is also pretty cake to run as a f2p player (I'm one myself). I use this guide (http://forum.naruto.oasgames.com/en/forum.php?mod=viewthread&tid=3571).

As for a good Earth main line up, the one I ran that was REALLY good was GNW Kankuro/Guy/Jigo but since you don't have any pains, perhaps I'd suggest running someone like Tsunade instead?

What ninjas/summons do you have? I could probably find another substitute lineup for you.

Generally looking for Easy but doesn't matter, I currently have Kakashi, Asuma and Hinata + EM which gives about 7 combo so I'm not too sure if there is something better for me.

Then yeah I'd use the Easy guide I linked. It's all F2P ninjas as far as I know. Your current team doesn't sound half bad. A quick team that I made in Simulator can get about 8-9 combo off of main mystery. I'll list all the stuff below

Main - Hinata - x

Sasuke - Kakashi - Clone

x - x - x

Talents are 2 3 3 2 2

Summon is White Snake.

Of course this was just a really fast team and I haven't really tried it but if you wanna keep using Kakashi and Hinata that'd be a pretty good team to use them in.