If you import your Paragon Shepard it starts an entirely new game, your Paragon Shepard will be unaffected by any actions performed in this new playthourgh.  But it never hurts to back up your save to a thumb drive.

I think your asking how to transfer a saved game from ME1 to ME2.  If that's the case you need to be a little clearer on your questions and not talk like a five year old.

Directions:
1. Open MassEffect2Config.exe either through the launcher or in your /Mass Effect 2/Binaries folder

2. Click the Save Games tab on the left column of the screen

3. Click Cop Mass Effect 1 Save Games

4. You will be prompted to locate the ME1 save directory. On windows it should be My Documents/BioWar/Mass Effect/Save

5. Click OK and then exit out of the MassEffect2Config.exe

6. You should be good to launch the game with your ME1 saves loaded.

In Nuketown no matter who wins, were all **** up by a nuke.

Don't get to attached to tactics that worked before, just because they were good then doesn't mean they are good not, people adapt and people change depending on the type of player they are facing.  I find the best approach is to play a few games and see how others play, if you see alot of people sniping, you may want to consider a silenced CQB class.  If people are using silenced weapons alot an AR with a gernade launcher can solve that.  You have to keep changing to keep up with new tactics and trends that crop up in multiplayer.

Its not a bad game, its just an okay game.  But in series know for great games that makes it bad.  Plus its more of just MW2 continued with bug fixes.

When you start out you only have three classes but you quickly unlock two more.  These classes cannot be modified but should give you a good idea on where to start with your custom classes, as for what class you want it all depends on what you want to do.  I have normally two class types loud and strong or fast and silent. The rough builds are below

Fast & Silent

Primary: AR or SMG (silenced with range or attachments)

Secondary: Pistol (normally akimbo 44 Magnum or Desert Eagle)

Lethal: Any (get familiar with all of these)

Tactical: EMP Gernade, Radar, or Conccussion Gernade

Killstreaks: Specialist (Marksman, Slight of Hand/Scavenger, Quickraw)

Deathstreak: Any (i prefer Last stand or Dead Man's Hand)

Perks: Blind eye, Assasian, Steady Aim(SMG)/Dead Silence(AR)

Loud & Strong

Primary: AR or LMG (Grip and a scope)

Secondary: Launcher (any launcher will do, lock on is easier)

Lethal: Gernade or Semtex

Tactical: Tactical Insertion or Trophy System

Killstreaks: Support (Ballisti Vests, Stealth Bomber, EMP)

Deathstreak: Any

Perks: Scavenger/Blind Eye, Blast Shield, Steady Aim/Stalker

On all of the perks be sure to take the time to unlock the pro versions as they will make you more effective.  Don't just follow these guidelines or online advice though, only you can tell what you are most effective at.

It is possible to get your EMS high enough for the synthesis ending without playing multiplayer at all.

In order to do this you must have played through all three games as a complete Paragon (it might be possible as a Renegade but I've never tried.)  You also have to complete every companion DLC for ME2 (Kasumi, Zaeed, and Shadow Broker) and every side mission in ME3.

It takes less time to play the multiplayer you only need about 65%-75% galactic readiness.

Both TIM and Saren believed that the Reapers were the key to unlocking synthesis and control, they were only partially right.  It was the AI god that was responsible not the Reapers.  The Reapers themselves don't want the cycle to end until the catalyst connects with the crucible, the Reapers believe they are averting chaos that results from evolution and instilling order.  However they were not fools the catalyst was likely a safeguard to prevent the destruction of the entire collective consciousness of eons of civilizations.  This knowledge is worth more than anything else and the universe.  When Shepard reached the catalyst the Catalyst realized that if the cycle was allowed to continue the next cycle would likely be able to destroy the Reapers without the Crucible at all, as the civilizations had gradually gotten more and more powerful across the ages.  Therefore to avert the loss of knowledge it presented Shepard with alternatives that would preserve this knowledge.

TIM and Saren both gave themselves over to the Reapers, willingly at first and later by force.  Indoctrination is a slow process if you wish to preserve the integrity of the person being indoctrinated, let us not forget that the less control a Reaper has over a person the more mentally and physically capable that person is.  Cybernetics can boost strength and stamina, but a person with free will has far more strength than either of these, free will is what drives us to be better and never give up, it allows us to overcome our enemies even at the cost of our own life.  Indoctrination can be done more rapidlly but requires the Reaper to be in close proximity or the use of other devices (dragons teeth), and Shepard never spent alot of time around Reapers.  The most time he ever spent near one was in the Arrival DLC and that wasn't a full reaper it was a sort of Reaper phone.

I don't trust the catalyst either, I don't turst anyone that makes more than me.  But it is just trying to preserve the Reaper's knowledge, it is not an agent of the Reapers nor does it control them.  It was merely programed to wait until it found an oppertunity for the cycle to be broken and when that chance arrived it was to preserve the collective knowledge IF POSSIBLE.

Also if you choose destroy the Quarians die too.

Originally ME2 was there to suggest at the existence of Dark Energy, specifically during Tali's recruitment on Haestrom.  Dark energy was supposed to be this force that was going to destroy the galaxy (don't ask me how) and the Reapers were trying to research a solution to this.  The ending for ME3 was supposed to be Shepard deciding between allowing the Reapers to continue harvesting in the hope that they would find a solution (thereby saving the galaxy for a future cycle) or stop them and hope that humanity could figure out Dark Energy on its own.

Unfortunately this ending was leaked and throw into the garbage bin.

I have no idea, its a great game.  I guess the people that hate it are just alot louder than the people that like it.