Actually, he said 120 amp.. but that's not really the point..
As far as voiding warrenties.. you have to read your warrenty stuff to see.. and I'd suggest asking your dealership about it.. Even though a bigger alt shouldn't be an issue, it might require regulator upgrades, etc..
Caps are pretty pointless.. they act as little batteries that can provide juice for fractions of a second, they will NOT increase the power your system can produce.. A lot of places refer to caps as 'voltage stiffing capacitors'.. they fill in gaps when your amps **** really hard, but can only fill for a very short time.. then they have to be refilled from your charging system.. so if the charging system can't keep up with the normal volume you are running at, caps aren't gonna help much (if at all) and you will still burn out your alternator...
As far as fuses go.. fuses are there to protect wires (for the most part).. Just because your amp has one inside that will try to protect it doesn't mean a short before the amp won't burn your car down if there is no fuse.. The first stop for your wire should be a fuse close to the battery.. and you should consider a fused connection each time you drop the gauge of the wire .. no fuse + short = fire (or at least super hot wires/melting/stinking)...
Hope that helps..
(1) Alpine CDA 7892 HU ($214)
(2) 12" Pioneer Premier 1241DVCs in sealed MDF box (gonna glass them eventually) ($69 each)
->removing.. ->(2) 10" Pioneer Premier 1041DVC's in sealed MDF box (gonna glass them eventually) ($59 each)
(2) Lanzar Vibe248 1200 watt 2 chnl amps ($119 each)
It's bump'n GOOD!
You can lead a horse to water but you can't make a moron understand...