If you are this much concerned you might not go at all... being on a bike and in north for the first time you will need a helping hand in many situations you might fall.. even professionals fall and slip and tuck and need free ride or have to patch up with other, at some place where security is tight alone riding is not allowed by security agencies and they stop people and send them in groups.
But thats a different story, you dont even need to mention that u have reservations every one has few.
1 - Yes you can go from Muzafarbad but as I see u r from karachi so first you will have to reach muzafarabd and from there to balakot and ahead, explore a little on Maps.
2 - Kaghan is good for stay contact Dr Omair here in pakwheels he knows few good hotels there.
3 - Yes Kaghan naran valley is expected to be completly jam packed and halted on EID holidays It would be a worst decsion to go.
4 - According to my experience when ur motor bike is fit A - Z it fails on first few kilometers, the only trick which works is to be ready to handle it nicely when it occurs.