I had not considered these two together. Looks like a lot of fun though!

First thing I would suggest is more mana rocks since youre in four colors you are going to need all the help you can get. I would definitely add the rest of the signets in there ( Dimir Signet, Orzhov Signet, Azorius Signet.) Other good mana rocks that could be added in...

Fellwar Stone: Since youre playing four colors its more than likely to hit one you need.

Chromatic Lantern: Insanely good and has been steadily decreasing in price last couple of months.

Solemn Simulacrum: card draw and mana ramp. If you happen to find one stuff it in there.

You also mentioned being worried about lack of recursion. A few ideas that immediately came to mind that might be worth checking out are...

Marchesa, the Black Rose: she rewards you for attacking and makes your creatures much harder to remove. She could be a bit tricky though with the life gain but could work with something like Cradle of Vitality. Just a thought.

Athreos, God of Passage: I know hes a little past the $7 mark but I thought he was worth a mention anyways.

Sun Titan: Just all around good and insanely cheap.

Whip of Erebos: Rewards you for attacking and also digs things from the yard.

I would also recommend adding in another land or two along with adding in a few more duels. Nothing is more frustrating then getting color screwed...

Temples ( Temple of Deceit, Temple of Epiphany, Temple of Enlightenment, Temple of Silence ). For the most part there pretty cheap (/annoyingly looks at the red blue land) and the ability to scry off a land drop is really powerful.

Lairs ( Crosis's Catacombs, Dromar's Cavern ): these cards are highly underrated and dirt cheap.

Command Tower: One of the best lands ever and little over a dollar currently.

Reliquary Tower: since it looks like youre going to be drawing a lot of cards this might not be a bad land to have.

Geier Reach Sanitarium: Another source of draw and a way to force opponents to discard cards to help trigger Sangromancer and such.

Some other cards that I think could be worth taking a look at...

Ayli, Eternal Pilgrim: Life gain and removal.

Sidisi, Undead Vizier: A 4/6 deathtouch that tutors.

Fact or Fiction: One of the better draw spells in the game.

Jori En, Ruin Diver: A reversed version of Kraum.

Mulldrifter: a good draw card and is just dumb with Blade of Selves.

Chasm Skulker: Gets bigger the more cards you draw. Also helps against board wipes.

Alhammarret's Archive: I cannot suggest this card enough for this deck. It would be insane.

All right thats all I got off the top of my head. Hope this helps!

wow mulldrifter is dumb with blade of selves ...never thought of that...wasn't even focusing on the etbs.

I think I misstated the lack of recursion bit...my default setting is; libraries are dumb...lets play EVERYTHING out of the yard... I'm specifically trying to stay away from that here. (my whip of erebos in sultai never lasts a turn ...evar)

at one point i had all signets but dimir (tht was keyrune for evasion) ... but it looked like too much...

solemn simi, chromatic lantern, command tower, reliquary tower omitted to try and stay on budget...put on the mental maybe later list....now i've just added alh.archive to tht list...forgot about that one....good stuffs. marchesa i thought about and abandoned... jori en & FoF ended up in my cut-pile. i thought about scry lands..but already have 15 etb tappedz (eeeek) i'm really hoping my mana fixing is ok as is but won't know for sure till i run it as paper a few times...other than the fact that fellwar stone (and Ayli) are part of crap i meant to put those in there list :P

LOVE Geier Reach Sanitarium .. didn't know that was a thing...awesome sauce!

thx for the imput and upvote Fallentesla got a few things from it and most of it looks like we're on the same page....