Yes, I've used it on FTA sats many times, real simple for those. You probably already know how to do it, but I'll run through the procedure of it.
Turn the meter on and then push the Option/Local button, you should see a arrow next to the L: slot at the left side of the screen, there you enter what sat you're working with, 95W, 121W, etc.
Push option/local again and the arrow moves down to the F: slot, there you enter the transponder you want.
Push option/local, SR: here you enter the symbol rate.
Push option/local, arrow moves to LO: here you enter the LNB Lo.
Push option/local, arrow moves to LNB: here you can select your LNB voltage, either 13V for vertical, 18V for horizontal, or blank for no power supplied from the meter. The arrows buttons next to the option/local button cycle through these options.
Push option/local again and the arrow moves down to 22KHz: Here you can select 22 KHz on or off. Use the arrow buttons to select.
Push option/local again and the arrow moves all the way down to the lower left hand corner box with the list number for the satellite in the meter. Once here, you can push the save/c button and it'll save what you inputted to that sat slot/number in the meter, or if you push any of the number buttons, the meter will come on so you can see your signal and quality readings and actively use it. Hitting any number button again exits back out into data entry mode and you can again use the option/local button to move through the different fields if you want/need to change anything.
When I first got my FS1, I had to enter my Lat and Long settings for my location into it, if you move the arrow [using the option/local button] to the sat/slot number box at the bottom left hand corner of the screen, then push and hold the zero button for three seconds, the arrow will jump over to LONG: and you can set your lat/long settings for your area. Your azimuth, elevation and skew in the top three boxes at the top of the screen won't read right until you do this.
I don't know if the FS1 will work with Ka or not, all I've ever used mine for is C band and Ku.
With FTA, looping the meter in line [in series with the LNB and receiver] through the two F connectors on the meter, allows the meter to be powered by the receiver. [Coax from the receiver to one F connector on the meter, coax form the LNB to the other F connector] Handy if your battery dies, maybe useful in your situation with the Direct stuff, to let the receiver power everything? Don't know for sure.
I found a few things on First Strike's website that might be helpful, maybe.

using a high frequency splitter to power multi-head LNBFs

Aligning DirecTv dishes
Those were from here:
http://www.firststrikemeters.com/fs-support/fs1-frequently-asked-questions/