do i need to make any adjustments to either my acoustic or electric, if I want to go one down on the gauge?
If you're keeping the same tunings and all, probably not. It won't be too big of a tension change.
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I went from D'addario 10's to GHS Boomer 9's on my Dean. It was a straight up change with no adjustments. There was a slight change in tone I'm not happy with. The 9's are easier to play, but I'm going back to the 10's when i change again. I keep all my acoustics setup with 11's so I can't help you there.
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yes i can
first of all it is a very bad idea to go to 9s in my opinion
tone is lost at 9s and tens are the perfect gauge
but if you think you are then yes especially on your electric it can change the action alot, you should adjust the tremolo if you have one and truss rod or get someone to do it for you

if you feel that the strings are too heavy to bend or something then you just need to practice. one thing to do is use more thatn one finger for the string and that'll help

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i changed from 10's to really light 8's and tuned down to Eb, and eventually my guitar started giving a little buzz, so if you can afford to you might as well have it set up how you want it professionally

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