No, you can't get Exclusive Abilities from the normal gacha spins, since Exclusive-rarity Abilities are only obtainable as Raid boss drops, through the Raid Shop using Raid-specific currency, or as a direct Robux bundle purchase.

The difference between Normal Spins and Lucky Spins is that Lucky Spins give better odds at rarer Abilities or Gadgets, while Normal Spins are the standard roll used more frequently during regular play.

Yes, you can trade Items you don't need for ones you want through the game's Item Conversion NPC, though the trade only works between items of the same rarity, at a 3:1 ratio.

Yes, you keep the Coins, Abilities, and Items included with my purchase, exactly as shown in the listing.