That tool works great if you're stripping a bunch of speaker wire but it takes too long to adjust to cut a couple wires. I'd rather use a box cutter to strip a few cables. Banana Plugs look nice and are easily removed, how often do you disconnect your speakers? I have banana plugs on the receiver and bare wire on the speakers. If I ever have to do a little clean up, its easier to unplug from the receiver using banana plugs.
+1 to banana plugs. They don't affect the sound, and once you've put them on, disconnecting / re-connecting wires to your AVR or speakers will never be a chore.
As long as its a solid connection, there will be no difference in sound.
IMO your best connection will always be with bare wire into the binding post. I use banana plugs from my wall jacks, but where convenience dictates it's always a bare wire connection. SpeakON connectors are another highly regarded option but I've never used them.
And a wire cutter/stripper is only about $10 or so from the local hardware store. Better investment than banana plugs unless the goal is to plug and unplug the speakers frequently.
Your questions are answered: Speaker FAQ
HT: Energy RC-50, RC-LCR, Veritas VS Surrounds | Dual CHT SS 18.1s | Denon AVR-888 | modified Dayton SA1000 | Antimode 8033C
Desktop: CBM-170 SE | SVS SB-1000 | Audio-GD NFB-11 | HK 3390
Headphone & Portable K7XX | HP150 | DX50 | E12
Screen: 120" Elite fixed frame
AVR: Onkyo TX-NR809
Mains: Klipsch RF-62ii x 2
Center: Klipsch RC-62ii
Surrounds: Klipsch RS-42ii x 2
Subs: Dual Hsu VTF-15H's
Sonos-Play 5 and Play 3
Sony Playstation 4
Microsoft Xbox One
Television: Mitsubishi WD65737 DLP
Processor: Emotiva UMC-200
Amps: Carver AV 806x/Behringer EP4000
Mains: DCM TimeFrame 600 Center: AT 453C
Surrounds: AT 251.1 Sub: Danley DTS-10
Blu Ray: Panasonic DMP-BD655