Similarly, the higher the tension, the less strings will deflect. Meaning you'll get both less power and less spin.
Unless you hit with an oversize racket, you'll be fine going 2 lbs above the bottom of your racket's tension range. Hell, Fed goes 2-3 lbs lower than his stick's basement tension.
Unless you hit really flat shots, what's there to worry about? No matter how powerful your shots are, as long as there's enough spin they'll land in.
(That said, if you're a 3.5 or 4.0, you need to work on your technique more than you need to worry about string tensions.)
6 x Head MGPMs, 3 x Head i.PMs, Gamma X-ELS