According to the Shroud MTG rules, it does not protect a card from the effects of other cards
Playtest cards are a great way to experiment with new strategies and combos in a deck without dropping tons of money
A card that's restricted in Vintage can only appear once in your deck, including in your sideboard
Priest of Gix 1.0 While a free 2/1 is great you have to have three mana to start with and it is so weak it basically costs you a card
Atmospheric Greenhouse Atmospheric Greenhouse wants you to cast it once youve already developed a board, and it provides an enters trigger that gives a +1/+1 counter to every creature you control
I especially recommend the cycle of common cards from The Lord of the Rings: Tales of Middle-earth , as they all make for great fixing options in Commander, Pauper, and even more powerful formats like Modern and Legacy on occasion