Minion of the Mighty + Scale Up is a great dragon combo to get some early plays

I love the concept of this deck. I play a Polymorph + Shape Anew deck and something that helps alot is lands such as Mutavault for a creature at any time. also Beckon Apparition would make a good Sideboard option as a weak form of graveyard hate while also keeping the same theme.

Hey I took another look at your deck and I'm more looking at your sideboard. I'd advise taking out On Thin Ice as you already are running a playset of Path To Exiles and I'd add Pithing Needle instead. The main reason is your deck is extremely vulnerable to Engineered Explosives which a sideboarded Pithing Needle can easily stop. Hope this helps.

Your deck is chaotic and all over the place. If your looking to be aggro you can't be adding like Ancient Copper Dragon or Niv-Mizzet, the Firemind without something like Minion of the Mighty to get them into play quickly. Alot of burn/aggro use cheap creatures like Monastery Swiftspear with prowess triggers with cheap spells like Lightning Bolt or Opt hope this helps

Your creature count is high enough you could go the Collected Company route.

Don't normally play vampires but im personally a huge fan of Sorin, Imperious Bloodlord + Ghalta and Mavren combo.