Yes it will make a difference, adding an inch to a wheel adds 12.7mm per side. So, not only will a 0 offset 10" poke out 12.7mm (1/2") more on the outer edge, it will also reduce your clearance to your control arm by 12.7mm (see attached). I think a 20x10 0 offset is near perfect as it would be roughly the same as a 20x9 -12. That offers a good little poke past a stock fender flare. I don't think any wheel manufacturer makes a 20x10 0 offset, asthe highest offset I have seen on a 20x10 is a -12. I think i've seen about every wheel on the whole internet.
The best way to think about offset is as the number gets smaller, thats the amount the wheel goes outboard. Stock is a 20x9 (or 18x9, 22x9...rebel may be different) with a +19 offset. if that number shrinks to a 0, it goes 19mm further away from the hub. And, as it goes negative it gets even further away, thus adding poke. Once you add poke though you reduce the scrub radius and run the risk of hitting your wheel wells. All a balance...