From a gameplay perspective, mortars are amazing as they use the large 5" template and you don't need to guess the range on them anymore. Cannons are awesome at what they do, but limited in all around usefulness. At 1000pts, most people won't be having large monsters to shoot at or other big warmachine things but most lists will be having at least a couple large blocks of troops, which the mortar would be key for.
As an Empire player myself, I try to keep 1-2 mortars and 1 cannon in my 2000pt lists, so having one or the other in a 1000pt list would make sense too (and you don't need two mortars at lower point levels either.)
I like swordsman for my armies because of the parry save and WS4 even though many of the people around here like Halberds for the str4 attacks. I do like Arch Lectors as my generals as well, because they are still Ld9, and they give +2 dispel dice which is huge. None of the Empire characters can fight their way out of a wet paper bag so losing an attack isn't that big of a deal. At larger point levels you can put your Arch Lector on a War Altar and he'll be neigh unkillable (and a great tarpit as such!). Lastly the Arch Lector makes one unit of flagallents become core eligable as well
Overall, the lists here look pretty solid. I <3 greatswords too, even though they always always tend to run for me on their stubborn leadership (including a reroll.) I stll bring them nearly every game.
Good luck with your Warhammer journey! If you have any other questions, don't hesitate to ask. Empire is awesome, and it always will be because it is the cornerstone of the WHFB world right alongside chaos.