1. Buses do no operate from Chaukori rather go to Udiyari Bend to either take Taxi to Munsiyari or First reach Thal and then change taxi to reach Munsiyari. You will easily get taxis to Thal from Udiyari Bend. Chaukori to Udiyari Bend (3 Km) , Udiyari Bend to Thal (25 Km) , Thal to Munsiyari ( 70 Km). If you start at noon from Udiyari Bend you can reach Munsiyari by 5 PM which is good enough. 2. Munsiyari is a off track place bus service is not available for most parts although some buses do run but Taxi is much better public transport. From Almora you can take taxi to Munsiyari which come from Kathgodam. They reach Almora by 9 AM. Alternatively you can take taxi till Berinag and then follow route of Thal-Musiyari. Taxi Frequency is good and wait for bus should be avoided. 3. I haven't be to Nainital but for nainital main bus stand still is Haldwani. No direct route is there to reach Chaukori. you have to change at Berinag and take a taxi which is going towards Bageshwar. One advice: try to put more focus on Munsiyari if possible, there is much more to explore than at chaukori. Also explore option of homestay in Sarmoli village of Munsiyari.