No, whatever happened on Mars has to do with issues of planetary geology and natural climate change that aren't issues for us. i.e. it's a term in the Fermi equation that doesn't apply to us anymore.
Sure, but a large body of water makes finding life much more likely. And if we find life on our doorstep, we ought to reduce our estimates of how unlikely abiogenesis is – suggesting the Great Filter is ahead of us, not behind us.
Still not sure how many planets can form life. We think you need water, certain gases, a stable temperature, magnetosphere to block solar radiation, planet like Jupiter to absorb asteroid like impacts...etc. I'm not sure if Mars ever had all that.
That predicate falsey assumes "life" can only survive in earth like conditions
Nope. I said we "think". So far we have only one data point. No idea if right or wrong :).