1/ it's been done a lot in the past all around the world and I can't think of one single accident directly attributable to "coasting in".
( it's not something I see a need to do however let's keep it in perspective shall we )
2/ how many backups do you need? You might as well fly an Aircraft with 10 Engines, 5 Hyd systems, 2 accumulators and an Anchor if you are that "conservative"
