Most Helpful Guy
1) You can play his game or mirror the same attention he gives u, if he he is worth it. When next he texts you reply 3 days later. whenever ghost u for a few days do it to him to. Never put more into something while the other is seemingly less invested. Your availability should be a reward to theirs.
2) Really its up to you. Do u want someone that texts u often? If yes then this guy is not the type you want. whether busy or not. The question here is how do u want to be treated?
Most Helpful Girl
Well, all you can do is decide if you want a guy who will disappear for days or a guy who will actually reply to you like a normal guy who likes and respects a girl.
Even if somebody is busy, it won't take 5 days to at least say "sorry, busy, will text later"
Always remember, actions speak louder than words.