Why did the Executor have to crash into the Death Star?

Agreed with Bib.

Also, "Oh, and just out of curiosity, was the Executor ever mentioned by name in the OT? And, when spoken, is the stress on the first or second syllable?"
Second syllable.

 

Did the Executor have a huge cannon it could train on a target?

Like, when Han (in ANH) says "it'd take 1000 ships with more firepower..." do the SD's just all surround a target and fire the turbolasers or is there a big-boy cannon that is reserved for huge targets?

If so, would the Executor have the biggest freakin' gun ever?

 

"do the SD's just all surround a target and fire the turbolaser"

Correct. The SD's bristle with guns. They can bombard a planet from space, and destroy everything on the surface. The DS takes this a step further with one big gun.

 

As originally scripted, Moff Jerjerrod (once the shield fell) was ordered by Palpatine to turn the Death Star upon Endor and destroy it -- a parting shot that would render the Rebels' victory meaningless as both fleets would be incinerated by the shockwave. This was in both the novelization AND the comic book adaptation, so it made it as far as the shooting stage.

The Death Star began to turn upon Endor as Lando and Wedge made their desperation dive through the station's interior. It was clear the station would complete its' turn and fire before Lando and Wedge could reach the reactor, hence Ackbar's line:

"We've got to give those fighters more time. Concentrate all fire on that Super Star Destroyer."

The crash of the Executor was supposed to slow down the station's turn (by disabling most of its' thrusters, I suppose, or by knocking the station in a slightly different direction, hence wasting time to adjust course), hence buying Lando and Wedge time to hit the reactor. Note that as the two fled the Death Star, the Rebel fleet was positioned directly between the station and Endor -- to catch any explosion debris, no doubt, but also to possibly take the blast meant for Endor.

Of course, Lucas cut out that whole subplot in post-production for the same reason AOTC's Droid Control Ship raid bit the dust -- to shorten and simplify the battle.

 

Well, in the film, you can clearly see that the Death Star had rotated to face Endor just before it exploded, so the Jerjerrod subplot could have still happened.

 

Very interesting stuff, indeed.

 

I'm no EU buff so I wouldn't know the answer to this question.

Did Jerjerrod escape in time or did he suffer Tarkin's fate?

 

Jerjerrod died aboard the Death Star.