Which pages are appropriate for these topics?

[Aswan jaguar]

You can ask anything you want here. We don't have a dedicated feature request thread at least not one that has been active the last 6-7 years that I remember so you can make one yourself here in the Manalink 3.0 forum.
About search in deckbuilder:
1) Right click on the first button and click on Tournament formats/expansions to select only cards from the sets you want or tournament formats.
2) Left click First button excludes the cards that are not real but help cards that are needed to run the game or modes like draft...
3) In search you can search for subtypes and anything the cards have in their rules text. You can search for a phrase using the " phrase to be included " .
4) If you are anywhere but the search button and begin to type a cards name it will take you to that card.

[drool66]

Also, what page or topic should I add a request for a card that has not been implemented and I would like to see added?

I'll try to code anything requested in this thread:
https://www.slightlymagic.net/forum/viewtopic.php?f=25&t=895&start=555