Build Up Period

[OsirisD]

So, my 4k TT was 16m48s, and as per instructions,
* this results in a 5k of 21m,
* a 10k of 43m(+1m adjust),

* 2k session pace of 04m18s, rounded at 04m20s
* 1k session pace of 04m10s,
* 400m session pace of 04m00s

Now the questions:

* what time should I aim at for the 5k run?
* at what HR should I run the easy runs? My aerobic zone(based on %HR Max) is between 132bpm - 150bpm. Should I be aiming for lower or upper limits, or middle?
* at what pace or HR should I run the longest run?