Hi chuckado, I know how you feel - I am curious about my manabase as well! By only seeing a list of lands it is difficult to tell if the choices are correct for the deck. Though, I can share what I have learned about building a mana base.
First, we need to look at what spells we want to cast on which turns. Example:
On turn 1, blue to cantrip, and black or green to play a Deathrite Shaman, or perhaps black to Thoughtseize.
On turn 2, white to cast Stoneforge Mystic or perhaps line up a Swords to Plowshares.
On turn 3, we hope to have double blue for Vendilion Clique or True-name Nemesis.
Figuring out the chances of drawing what we need is based on "hypergeometric distribution," and there are nice
charts and
calculators that already exist for our reference.
Next, compare what we are doing to others that have succeeded already. One thing I noticed is that you play 2 Scrubland (where many others might play 1) along with the 3 U.Sea means you might have more black mana symbols than other decks (perhaps you have Liliana of the Veil?). Then I see you have both a Karakas and a Plains, so maybe you have some spells that cost double white too? You might have to take a look at the balance between blue and non-blue sources in your deck.
As for including basics, I would say that depends on how many of your opponents play Wasteland, Blood Moon, etc. (meta-game call). Now that I think about it, I would want a basic if having that color was important to my game plan or if it helped me get out of a situation where my mana was under pressure (ex. Plains for Disenchant on Blood Moon). You might ask yourself, "When do I want to fetch an Island or Plains over a dual land?"
Mana bases don't get much greedier than Deathblade, and with Sylvan Library + Abrupt Decay in my deck list, mine is high on the greed scale. My land selection differs from your's in part to green sources taking up slots formerly held by basics. I might get blown out by
Price of Progress or
Back to Basics.
As for just figuring out how much mana the deck needs/has, I count all 4 Deathrite Shaman as *almost* 1 land, as it dies often and depends on fetchlands in the early turns.
In regards to cantrips, Patrick Chapin (2015) explains, "cards like Ponder can help fix your mana. As a general rule, cheap cantrips like this can be looked at as being worth between 50% and 100% of your mana ratio. For instance, if you have 24 lands in a sixty-card deck, that is 40% land. If you add a Ponder, you could say it increases your land count by between 20% and 40% of a land" (pg. 49). For me, I have Deathrite, Brainstorm, Ponder, and Sylvan Library as adding 2.5 to my land count.
Anyway, I hope this information gives you a little more to think about over the next few days :tongue:.
References
Chapin, P. (2015). Next Level Deckbuilding. 
