If you are worried about survivability at low levels, maybe grant max hp, then one less then max cumulative per level after until you return to the average?
Ex. A Cleric would get 8, then 7, 6, and 5 thereafter.
Or, start your game at 3rd level.
For my own game I'll run in a few months, we are reducing HP bloat in PCs and monsters:
Level 1: PCs get max HP at and their HP modifier.
Level 2+: PCs only get their HD, no more HP modifier.
Monsters all have half HP (round down, minimum 1).
Our reason for those rules is to speed up combat because it takes too long with the huge amounts of HP compared to damage. We thought about doubling damage, but this keeps the numbers smaller and easier for some of our group to deal with (mathematically challenged and such).