You really need to have a solid surface for large tiles. The actual tiling is not the hard part. You need to make sure you have a very very flat concrete or backer board subfloor.
As for installing the tiles the only thing "harder" is that you will have to back butter your tiles. Also if you mess up a cut bad it costs you more.
The flip side is if your subfloor is set up right you can have a really nice looking kitchen floor. The big tiles do look nicer and clean easier. Also if you start in the right spot all/most of your cut edges can be hidden easier.
Protecting the Cable
National Electrical Code 2014
Article 300 Wiring Methods
I. General Requirements
300.4 Protection Against Physical Damage.
(F) Cables and Raceways Installed in Shallow Grooves. Cable- or raceway-type wiring methods installed in a groove, to be covered by wallboard, siding, paneling, carpeting, or similar finish, shall be protected by 1.6 mm (1/16 in.) thick steel plate, sleeve, or equivalent or by not less than 32-mm (11/4-in.) free space for the full length of the groove in which the cable or raceway is installed.
Exception No. 1: Steel plates, sleeves, or the equivalent shall not be required to protect rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, or electrical metallic tubing.
So you have a couple options.
Free Space
Run the groove deep enough, so that there's 1 1/4" of free space in front of the cable.
Steel Protection
Protect the cable using a 1/16" steel plate, or sleeve. Or install the cable in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, or electrical metallic tubing.
Dividing the Circuits
National Electrical Code 2014
Article 210 Branch Circuits
I. General Provisions
210.11 Branch Circuits Required.
(C) Dwelling Units.
(1) Small-Appliance Branch Circuits. In addition to the number of branch circuits required by other parts of this section, two or more 20-ampere small-appliance branch circuits shall be provided for all receptacle outlets specified by 210.52(B).
III. Required Outlets
210.52 Dwelling Unit Receptacle Outlets.
(B) Small Appliances.
(1) Receptacle Outlets Served. In the kitchen, pantry, breakfast room, dining room, or similar area of a dwelling unit, the two or more 20-ampere small-appliance branch circuits required by 210.11(C)(1) shall serve all wall and floor receptacle outlets covered by 210.52(A), all countertop outlets covered by 210.52(C), and receptacle outlets for refrigeration equipment.
Exception No. 2: The receptacle outlet for refrigeration equipment shall be permitted to be supplied from an individual branch circuit rated 15 amperes or greater.
(2) No Other Outlets. The two or more small-appliance branch circuits specified in 210.52(B)(1) shall have no other outlets.
Exception No. 2: Receptacles installed to provide power for supplemental equipment and lighting on gas-fired ranges, ovens, or counter-mounted cooking units.
So as far as your plan for dividing up the circuits, you're spot on.
Best Answer
Do it the same way your other cabinets are done so everything is the same height.
Also removing the tile is a little bit tougher than you think. You can probably do it with an angle grinder but you risk the tile chipping badly or cracking. Going this route will also require molding over base plate to cover flaws. (and I almost forgot, when I have removed tile in past for things like this it was a PITA sometimes to actually make the area flat.)