As an answer to your question about combos being necessary i'd say: No not strictly necessary, but there's definetly a reason everyone plays with them...They allow you "free" wins from time to time, and gives you a shot at winning a loosing battle.
Here's the "main" combo's for Type1 Control decks today:
Painter's servant/Grindstone
Painter's servant -

Artifact creature - Scarecrow
As Painter's Servant comes into play, choose a color.
All cards that aren't in play, spells, and permanents are the chosen color in addition to their other colors.
1/3
Grindstone -

Artifact

Put the top two cards of target player's library into that player's graveyard. If both cards share a color, repeat this process.
Now obv. if painter's servant is in play the entire library will be milled by the grindstone...
Time vault/Voltaic key - This is probably the most popular currently:
Voltaic key -

,

: Untap target artifact.
Time vault -

Artifact
Time Vault comes into play tapped.
Time Vault doesn't untap during your untap step.
If you would begin your turn while Time Vault is tapped, you may skip that turn instead. If you do, untap Time Vault.

: Take an extra turn after this one.
Well, again obvious....if you got both in play, you got infinite turns.
Goblin welder/Thirst for knowledge - A bit old by now....but some people still use it

Goblin welder -

Creature - Goblin

: Choose target artifact a player controls and target artifact card in that player's graveyard. If both targets are still legal as this ability resolves, that player simultaneously sacrifices the artifact and returns the artifact card to play.
1/1
Thirst for knowledge -

Instant
Draw three cards. Then discard two cards unless you discard an artifact card.
Do note that thirst is the main draw-engine for almost every Type1 control deck....Now the idea is to discard a strong artifact to the thirst and then weld it in....Usually Mind slaver or sundering titan.
And one last combo, not so popular, but it's decent:
Auriok salvagers/Black lotus
Auriok salvagers -

Creature - Human soldier

: Return target artifact card with converted mana cost 1 or less from your graveyard to your hand.
With black lotus, that's infinite mana....The deck is basicly one big combo, with every card contributing...the deck often wins just by beating though.
And here's a link to a thread about the deck...
http://www.themanadrain.com/index.php?topic=37151.0Here's a good search engine to view cards:
http://ww2.wizards.com/Gatherer/Index.aspxAnd now for some criticism...First of, your deck has a very slow and rather small draw-engine...I'd probably switch it out for Intuiton + Accumulated knowledge, Thirst for knowledge or Dark confidant (use the link above to view the cards

) You really do need to draw cards if you're a control deck.
Serendib efreet probably isn't the optimal win-condition right now, Tarmogoyf is probably the best deal you'll find if you want to win with creatures...Otherwise there's Tinker/Darksteel collosus (or inkwell leviathan)...And i'd probably add in Time vault/Voltaic key.
For disruption:
4 Force of will is a must...After that you've got some potentials:
Mana drain
Duress
Thoughtseize
Negate
Mana leak
Rune snag
Chalice of the void
Stifle/Trickbind (combo's with phyrexian dreadnought....getting a 12/12 Trampler for

or

is a pretty good deal)
Wasteland and strip mine are also an option....I'd use gorilla shaman aswell if you go that route.
I'd like to write more, but i simply don't have the time right now, i'll try to get back to this thread soon though

One last thing i'd like to say is, check out this thread...I think it might suit your style:
http://www.themanadrain.com/index.php?topic=37191.0/Zeus