Mulldrifter is better than divination in a vacuum (discluding cards such as Runechanter's Pike, Quicken, etc...)

Hey, love to see someone getting into UW control. First off, to get a more competitive build will be a little tight on the budget.

First off, your mana base needs to be better. Some great budget options are Prairie Stream, Glacial Fortress, and Port Town. The reason you should consider these is that they have a chance of coming into play untapped, and while control can generally survive a few tapped lands, having as many as you do now would be deadly. Temple of Enlightenment is one of my favorite tapped lands though. I have personally been very impressed with Field of Ruin over Ghost Quarter. Once you're able to put a good amount of money into it, go for Mystic Gate (only one), Flooded Strand, Hallowed Fountain, and Celestial Colonnade.

I'm a big fan of big flying angel win conditions. Torrential Gearhulk is fantastic, but just make sure you're running enough instants to make it worth it. Nyx-Fleece Ram is definitely a sideboard card, don't run it in your main deck. 4 Wall of Omens is a pretty good defensive option.

Dissolve is my favorite counterspell, but you shouldn't be running it in modern. 4 Mana Leak. 4 Remand, and 3-4 Cryptic Command are the usual counters to run. Disallow is pretty interesting though. You should not be running Condemn, it was some pretty early Death's Shadow sideboard tech, but there are better options. You will definitely need to invest in a playset of Path to Exile, luckily they're at a pretty low price right now. Instead of Jace's Ingenuity, cantrips like Serum Visions, Opt, or Think Twice would be better options.

I appreciate the enchantments, but Detention Sphere should be making it into the deck over Banishing Light.

I would not run Divination or Ugin's Insight. Your board wipes are pretty spicy, but a little slow. Supreme Verdict is the most typical UW board wipe. Wrath of God and Terminus are other great options. Terminus is a personal favorite.

Planeswalkers you should consider running over the ones you currently have are Jace, Architect of Thought because his +1 will protect you quite well while the -2 is a fantastic source of card advantage. Elspeth, Sun's Champion will win you the game if she goes unanswered, pumping out little dudes with a board wipe at the ready. Narset Transcendent shines in instant/sorcery heavy decks. Gideon Jura is another great planeswalker. All of his abilities fall into control very well, saving you from attacks, removing opponent's creatures, and beating face.

For your sideboard, Blessed Alliance, Rest in Peace, Celestial Purge, Relic of Progenitus, Hurkyl's Recall, and Negate are all great.

Other great cards to consider; Geist of Saint Traft, Vendilion Clique, Entreat the Angels, Secure the Wastes, Faerie Conclave, Sphinx's Revelation, Baneslayer Angel, Dispel, Spell Pierce, Spell Snare, and Jace Beleren