I don't believe that deer will refuse to come in 'per say' when they smell freshly cut limbs.....but I do believe it will make them more cautious than they normally would be for a short period of time... Limbs fall out of trees all the time during storms and heavy winds, so it's not all that uncommon in a deer's world.
What I prefer to do when putting up a treestand during the season, or even before the season is this... when I cut limbs and branches I will drag them away from the stand site at least 40-50 yards and sometimes pile them up or use them to direct deer toward my stand site. If there is a way to create a small funnel by using cut branches, I will try to do that. It doesn't take much to make a deer change directions slightly by selectively placing foliage here and there.
If you need to trim out shooting lanes, by all means do it. Just drag the limbs away from your setup a little ways and pile them up, or use them to route the deer to you.
I operate roughly the same way as Chad...
Anyone that has hung a stand with me, knows I'm a shooting lane cutting sum beech when I hang them in advance of the season. I like to be able to shoot at least 4-6 lanes in a full circle of my stand, and I want to have a couple long range bombs. I'll shoot 50 yards, so that opens up some shots that I take full advantage of on my early hangs. I also use the stuff I cut to "direct traffic" so to speak. I've had great success with that in the past.
Now if I hang in season, I will cut if I absolutely have to. But I try to limit the in season cutting. Sometimes, you just have to cut a few things to make it work. I look at it like this: I would rather have the shot and risk the buck being skittish over the smell of a cut limb, over not cutting that limb and having him lick his ass for 5 minutes using that limb for cover. If I can easily and quietly cut it, I will and then drag it to the side somewhere I don't expect deer to encounter it.
I can tell that things are going to change for me with the LW and Millennium combo. I plan to sell all of my stands next year and go exclusively to stands prepped with climbing sticks and Millennium brackets. In places I don't want to leave stick, I'll use the LW's to hang them. I bought the GamePlan Gear Treestand Transportation System and it makes carrying just the Millennium a breeze. I'm all about the comfort nowadays, I can't do the small hang-ons anymore...