Gaining life, by itself, does nothing
On the one hand, you'll definitely get more value out of your energy-producing creatures than your opponent will, but you really don't want to give your opponent blockers, so it gets cut
In Global Settings, or settings for a specific template, change "Symbol Render Mode" to None
Cards graded by a professional grading service can often command higher prices
Giving +3/+3 to any body will make it a decent threat, put it on a flier, lifelinker etc and you are getting even mroe value
Edge of Eternities Commander (EOC), Stellar Sights (EOS), and Special Guests (SPG) are Commander-, Legacy-, and Vintage-legal sets, and individual cards are also legal where already available in other formats