If he decides to focus more on leveling than power until level 80 then if he ends up with a 25k+ power at level, it's going to be very hard for him to get to 40k at level 85

The majority of exp you'll going to get is from following the story missions in the plot instances. So people will just only do plot instances they have already finished or collect ninja fragments from elite instances. From there, people can stop completing the daily practice but if you're on in a guild with not to many players, it is advised not to stop doing them since they count towards the guild's activity rate, which determines if you get to participate in GNW.

Just don't do the main plot quests if you decide to slow down leveling. The kakashi daily missions count towards the minimal activity of 200 for groups to be able to sign up for GNW. Go look at your group's main page and see if the 3-day activity is higher than 200. If your group c*ways get it over 200, then you don't have to do daily. If your group is having trouble getting it to 200, just do the missions just so your group can do GNW. Only do Kakashi weekly that give out seal fragments.

Do nine-tails only for the coupons and you don't have to try as hard since the higher rank you are the higher the exp you get. Sweep elite instance so you can build 5* characters so you'll be able to refine them. Sweep plot instance to get awaken materials so you can increase power. Just try to do the events for the items, not for the exp.

How many seal scrolls you have? Go for han first then roshi.

Yeah forgot to mention why to choose han first over roshi. Like what SetSet777 said, once you get to level 70, the difficulty in pvp gets harder because of these types of teams. These types of teams can be created from getting ninjas from kage treasure (mei, darui, danzo). I have *t that runs the han, sailor, mei or kabuto as a water main and I can face people that run lightning/water blitz teams and have higher power (by a little bit). Han's mystery allows you to remove the buffs these teams rely on to get a 1-turn kill.

I don't know if you did this but you should at least awaken 12 ninjas for matsuri, ranked, and survival trial before you try to unlocking instances. Stop at level 70 as you are just limiting how much exp you get then you normal do. I also farm materials to create a surplus so once I am able to upgrade/awaken I can do it once I able to rather than waiting. The only time for you to resume doing the story line is just getting to the instance that gives you the awaken material and make sure you stop there and continue again after you max. Because of certain story line missions, you might level too fast depending on how much exp it gives you. Black market helps a lot with getting materials you don't have access to. Also, don't forget you get do elite instance to farm frags for 5* ninjas to refine the frags for iruka so you an excuse to use your stamina.

Even though you can't sweep, you can still get the items. You just have it manually collect all of the treasure chests in the instances. Either increase your power or find a lineup to get the instance to 3*.

If you hit level 80, you should have more than 40k to be at least being able to compete in events like sage.

But in terms of being competitive, it isn't a good bp at level 80 and you won't be able to complete against someone who level froze much earlier. Also, at the moment, you unlock all treasures at lvl 70.