You can do just fine with a loaner character on the offense, though it does make you a bigger target and means you cannot play as many games before getting hit.
If you are playing X-force Wolverine, you should be playing the Black/green AP boost as that powers his attacks. You can use +3 Black/Green AP boosts and +2 all AP and conserve some of that HP - you start with 5 green and black which means you are one match away from an X-force attack and two matches away from a Surgical Strike. Hood makes it go faster as well, of course.
Playing skills is just learning what moves benefit you the most and who is the most urgent to take out. For example, if you face another Hood you should probably take him out immediately, but learning who is most important to take out is tricky. When you lose a game, try to analyze what went wrong and see if you do better when you tackel the problem in another manner.
The thing is that he doesn’t have a fully covered X-force. That’s why I think his roster is undercover to aim at 1300. When I said I use green/black +1 X3 and green/black 50% is when I use patch berserker at 5 green and let my Hulk get angry at 5 black to produce tons of green on the board. For now I would save as much HP I can early in your game to buy that last cover you would need to fully cover a good character and not have to wait few months to win it. If you only spend hp on 2 3 hour shield and reach 800 you net good bit of hp every PVP. Once again that’s just me. As a F2p player I had to manage my HP carefully and be content with top 25 or 10 and 800pts.
Best is to have is the +50% 
+3 AP
+3 all AP
Reach 700+ I try to use shield hop already two match per hop.
Need to do the shield hop as early as I can or what?
I will get x2 30-50 point fight then shield. Search again n fight x2 match then shield.
As I’m ok to spend 1k hp to reach 1300 point as I will buy Heath pack too when I needed.
At any rate it is probably overkill to aim for 4* covers when you only have 2 fully leveled 3* characters. Doesn’t hurt to practice, but I agree that it is a good idea to conserve HP at least until you have a full roster.
How then is a full roster?
All the 3* is at L166?
All of them is probably overkill, but as long as three-stars fill gaps in your roster you should probably prioritize them. If you want an absolute number… When you have 10-12 lvl 166 maybe?
Ok that is still a very long way to reach that stage I think.
Next I will max out is hulk.