Your typical delver deck.
I went with this as the formula: 6 bounce cards, 5 counter spells, 6 draw cards, 5 Equipment Cards. Keeps your opponent guessing what you drew in your opening hand.
I'm not going to explain my choices for every card as this is your typical delver deck and some of these cards just don't need explaining. but i will explain why i picked the cards that make this deck unique among'st it's brethren.
Cryptoplasm - He is your safety net. he handles close to anything that slips through your bounce and counters. he is your thief of ideas and your defender. he can be your opponent's best strategy turned against them. all while being your safety net. If i had another snapcaster i would probably run them as two and two however.
Distant Memories - good for a one of. Most people go "awww. is'nt that a nice trick for four mana." and yes... i think it is. granted it normally sits in my hand for the entire game it's there too fetch what i need, IF i run out of answers. Or if i'm in a winning game... it just buffs my already tight grasp. it's a late game card, and most people will give whatever it is you seek too you over the risk of you getting 3 cards. especially in this deck where the cards are not intimidating on there own. Temporal Mastery in the sideboard because most of the time... i find i win games before i get to that high of mana.
Sword of Feast and Famine - granted you see this a fair bit, but i thought i would mention why. IT UNTAPS YOUR LANDS! i dont really see a strong need for any of the other swords in this deck. just this one. throw it on a unblockable and you got your lands back for bounce or counter.
I would love to run Cavern of Souls but alas... i have none.
Have you considerd Increasing Savagery? I made a similar deck, deck:increasing-unblockable and having permanent buffs on your deck:invisible-stalkers is great.
This looks like a straight up aggro deck with light control elements. I'm not sure what you mean by its versatility other than the sideboard options. That is fine- I have no problem with the deck list, I'm just not sure what you mean when you say 'versatile.'
I think if you want to take advantage of the pike you need less creatures and more spells. All of your creature choices are great- just run fewer. I would personally run less Cryptoplasm and Mayor- they don't have evasion. Increasing Savagery would be excellent in this deck. Hunger of the Howlpack and Travel Preparations would go in that same direction.
Evasion turns combat into a modal style- instead of your creatures vs. their creatures, it's a footrace between you and your opponent. I think you should run a boatload of bounce- Unsummon, Vapor Snag, and Disperse- so that while you're consistently hitting with Stalker or flipped Delver, you're also disrupting your opponent's game plan. Hope this helps!