My responses in bold. I was there last May.
Is it good to visit Toli Peer in April?
Yes, April would be fine. May was too hot since Banjosa is not at a high altitude
What about weather condition?
Would be fine. Hot under the sun but good in the shades and also cooler nights. Also depends if it rains on or just before those days. Keep a half-sleeve sweater just in case.
What about Road Condition?
Average to below average. Pindi-Kahuta was U/C last year but I suppose it may be finished by now. Occasional bad patches half the way to frequent bad patches on the other half. But nothing you cannot easily manage on any car. Rawalakot to Banjosa was also quite bad but under repairs last year.
Can I go there on bike? (Honda 125)
Sure, but I thought you wanted to go with family?
Is it safe place for family?
Yes
Please suggestion beautiful places to visit there?
Add Ayubia/Nathiagali to the tour if time/finances permit. Banjosa is more beautiful in pictures than in reality and Toli Pir is simply a "maidan" though much cooler as it is at a higher altitude. You can easily see both places in a single day.
What about night Stay toil peer or Banjosa?
The private houses/hotels at Banjosa are not really worth it. They are shabby and do not offer great views. Unless you can get the Forest or Wapda or Army rest houses, do not stay overnight at Banjosa. Nothing at Toli Peer itself but some good guest houses on the way. Plus being at higher altitude, they should provide cooler atmosphere.
Should I stay at “Toli Peer Guest House”? (Here is website of the toil peer guest house “tolipeergh.com”)
Seems OK but there wasn't too much rush so it should be OK to visit, see the rooms, and bargain on spot to get better rates. How much are they charging for the room?
Banjosa is a good place for a small excursion but remember that it is about half the elevation of Ayubia and about half as cold and green. It is an artificial lake. Best enjoyed if you want to relax there by renting army/forest/wapda rest houses and to be visited in March/April.