In this case, Im being very suspicious of any non-creature (and especially non-permanent) spells that dont strongly synergise with our core mechanics
its going to get the most expensive permanent the opponent controls, every time
Life Insurance: Its been a long while since we saw a useful extort card outside of Crypt Ghast and Blind Obedience
Life gain really isnt that powerful in a format where everyone starts with 40 life, and the difference between 3 and 4 mana is often huge, making this an excellent tradeoff (and a bit of consolation if you hit something of yours in the process)
Helm of the Host, on the other hand, will create a nonlegendary copy with haste each combat, earning you more and more triggers
Im glad you included the W Stamp filler