fly like a butterfly,sting like a bee

Yes you do need boots. Without boots you’re noticeably slower than anyone else on the map that has boots.

There are certain general concepts as to why boots are always suggested. I get that you want to go with a build that passes on it, since it's an item that falls off in use late-game especially with the replacement with Elixir of Speed. To that end, it's always interested me when there have been feasible options to skip boots/shoes.

That said, I can see you getting away with this kind of build, but it's awkward. Yes, you'll have reasonable MS once you finish Atalanta's Bow, but there are some other concepts that should be addressed.

1. What mode is this for? Conquest, or other? If for Conquest, are you picking up Hunter's Blessing at the start?

2. Power curve. What is meant by this is stages that you get new items, and at what time, and how well that transitions your damage potential. There's a reason Shoes and Boots are considered core/meta...for a price lower than any tier 3 item, they offer a LOT of value. At the stage you'd first get Atalanta's online, the enemy, if considered relatively even, would have completed Warrior Tabi or Ninja Tabi, and be working into their second main item.

3. This power curve concept also applies to more expensive items. There are several reasons you don't typically get a high cost item like Deathbringer, Rod of Tahuti, or Heartseeker early in a build. Neither Atalanta's Bow nor Wind Demon are that expensive for T3 items, but considering similar pricing for a more standard setup (let's say you go straight into Atalanta's and skip the Blessing), you could get Hunter's Blessing, Transcendence, and Ninja Tabi (that combo is 150 gold more expensive so is a good comparison). As an FYI, at this stage, your average DPS with the standard build is going to be higher, you'll have 10% CDR to go along with it, your abilities will hit harder due to higher base power, and basically unlimited mana. That's a rough tradeoff, to be honest.

It's good at least that you build The Executioner into this build. And while I can also see the appeal of boxing advantage with Poisoned Star, you're actually going to impact your DPS potential yet again by delaying the harder hitting Deathbringer (about 80-90 less damage per second on average, in fact). And before you build in DB, you're getting Heartseeker, which, although a strong overall item, is NOT optimal for Cupid in most cases. Keep in mind, outside of his ult, he only has 1 damaging ability that the HS passive will apply to. HS is typically best used on high power/pen builds on gods that have multiple (read: 3 to 4) damage abilities, where it can apply a lot. So HS isn't really a good item either, unless you were maybe trying to max its potential out by focusing on CDR and pen...getting a build more like Trans, Ninja, Jotunn's, Brawler's, Titan's, and HS for example. At least there, you could get more HS procs due to the 30% CDR built in.

In any case...several reasons this isn't really an optimal build for Cupid though again, I support theory-crafting to avoid the standard MS items.

Why don't you say something then?