1

That's a lot to fit in, in eight days, even with the luxury of an open jaw flight in and out.

I suppose you could fly everywhere which would save a lot of precious time. I think Yangon Air do a one day per week noon flight between Heho and Nyaung U (Bagan).

2

NO skip Mandalay and save valuable daylight exploring time during days by using overnight bus OK overnight bus Yangon to bagan same day you arrive (take it you arrive airasia 8am flight)
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so 2 full days bagan and early morning bus to Inle 3 days then back early after breakfast to Kalow spend whole day here then 530 -7pm catch overnight bus back to Yangon and spend last full tiring day and night Yangon and after early breakfast head for airport for 8am flight to BKK
flights to and from heho can be cancelled and delayed so no fun sitting all day at an airport with only 7 days in Myanmar

3

You will spend all of your time in Burma in transit - the fascinating buses and bus stations, rough roads, etc, - and won't have time to experience the place.

4

the bus journeys are an experience in themselves and the Engish speakers on the buses often want to help you at food stops and talk to you about myanmar and also test your culinary tastes or maybe even treat you to a ley peye at roadside stops. This is the real Myanmar so don't miss this side of it, the road from kalow to Bagan by day is great first trhough the mountains and village life first hand plus the truck stops on the way then after Thazi the great Burma teak storage yards next crircle through Naypaidaw the new capital that is more like surrey stockbroker belt than anything Burmese and then through meiktila past the lake and stop on way for breakfast and when you arrive Bagan around 3pm check in Hotel and enjoy a meal at shwe moes just along from roundabout and if you really want English pub food then great French haute cuisine at new place, weatherspoons further along opposite pan cherry
better than sitting in Bagan airport wasting all morning waiting for your delayed flight to Heho to fill up or cancel out completely till next morning.
just enjoy the moment youll be backl

5

Should be doable, not ideal, but doable. As long as transport doesn’t let you down. Montyman has a point, the bus trips still give you some insight of the place, although some stretches were same-old-same paddy-fields or miles of undulating hills. Personally, I'm not a fan of the overnight bus trip; I'm usually hung-over for the next day, so missed the scenery of the trip and wiped out the next day anyway.

6

It is great your trip itinerary,

7

I find if you take the overnight bus say from Yangon to Mandalay /Bagan/Inle and I've done all three and back at different times you arrive say Mandalay 5am grab a room (although now might be more difficult and if not being used you can step right in crash for a couple of hrs till say 9am and head off for that days adventure. I know many flights to and from Heho are cancelled and delayed through misty weather in that area. hence I suggest the bus for such a short stay at least even if delayed through breakdowns they will get you there