One month in Cambodia

I like to enjoy hustle and bustle and a fast pace, but also enjoy chilling out in very laidback places, though would prefer to explore on a motorbike than just sit around watching the day go by.

~ Day 0 - 10: I will enter Cambodia north of Stung Treng from Laos and will head straight to Ban Lung for at least 10 days to experience the 8 day trek into Virachey National Park. This is my only planned organized tour in 6 months in SE Asia as it really appeals to me and isn't too expensive.

~ Day 11 - 14: I will travel using local transport to Siem Reap with no rush whatsoever. I will stop over in a few locations, definitely in Preah Vihear, on the way and probably rent a bicycle in the odd area if possible.

~ Day 15 - 22: I will spend around a week in Siem Reap with 3 day AW pass, and will head north with a motorbike toward the Meanchey provinces no doubt in pursuit of a little adventure.

~ Day 22: I will travel straight to Phnom Penh. This is the part I'm not happy about... I'd like to spend a good amount of time slowly travelling and stopping in Kompong Thum / Cham provinces, or going the other way and stopping in the Koh Kong corridor, but will not have even nearlly enough time according to this rough itinerary.

~ Day 23 - 26: I will spend some time in PP enjoying the day and night life, and then head south to the beaches.

~ Day 26 - end of the month: Sihanoukville and Kampot appeal to me, and then I'll head through Ha Tien and straight to Phu Quoc island for at least a few days.

So my problem is this rush from SR to PP which skips out the middle of the country and the Koh Kong corridor! My questions:

1. Do you think I'm spending too much time in each place? I'm very keen to enjoy life in each place and not just be a rushing tourist and so feel I need to spend a good amount of time in each.

2. Should I spend around 45 days or so (or even 60) in Cambodia so as to include Kompong Thum / Cham, Mondolkiri, Koh Kong corridor etc?

3. I will enter Cambodia at the start of March and so would be in South Cambodia in April which is called the scorcher month, is it that much hotter than March?

Thanks!