Really digging this! Not 100% sold on the commander but here are a few suggestions that felt good imo.
Serra's Embrace could be swapped to
On Serra's Wings you'll lose +1/+1 but gain
lifelink which seems to be a thing here and it's definitely on theme. Then there's the new rampdog
Loyal Warhound and you also had some stuff giving
lifelink counters -
Spirit Loop could work here, it usually comes back and it's
lifelink without being
lifelink so if you have both it and
lifelink on something you get double the life.
I'd try to get a few more dogs in in general but seems like fun!