It will probably run and drive fine but as you inccrease the load on the engine (and boost) there will be a boost level that it starts to stutter. What happens is that the resistance increases with age and the plugs wear away. Wires crack and and leak and as cylinder pressure increases so does the amount of voltage that it takes to jump the gap.
This is what brought me to this board. I had never owned a superharged car. I drove it on a 5 hour trip and when I left the car was fine. about the time I came into the town I was going I was getting into some mountians, I had the ruise control on and as the boost gauge would reach about 5psi it started bucking. I have a 5speed car so I was in 5th and had to down shift to maintain speed. It really scared me since I was so far from home with limited tools. It only happened when I would reach 5psi. I drove all the way home after a few days (it was like Thanksgiving) and just babied it.
Over the next few weeks I asked everyone I knew and this included my Dad an aircraft mechanic from b4 I was born. A mechanic everybody at my work uses. Only my Dad said it was an ignition problem, but didn't know why exactly it was at 5psi. Then it got worse, it was about 3psi then 0 then -10 in/hg. Finally after about a 2 months of checking this and that (Checked EVERYTHING) I saw it on this board. Plugs and wires. Couldn't believe it, and really didn't want to do them (take a look you can't see nan one of them plugs from the top). Changed them after nearly choking on a $75.00 bill for for 6 double platnium plugs and 6 stinking wires, then I had to get the thing up on ramps and contort myself around to get them. Car ran like a top after that.
BTW you will need to use Double Platnium plugs only and don't use Bosch plugs. Also make sure that you baby your friends car as I know you don't want to have to change headgaskets on it as well. If your friend is letting you use it I suggest you just use it as basic transportation and don't get on it. These cars will pop a headgasket in a heartbeat. Done that too. Costs about 800-1200 for a shop to do it. 300-500 if you do it.
Jeff