had a quick question, hopefully corduroyEW could answer me, and sorry if this has been posted before, i couldn't find it using the search button

but i'm about to purchase a Larrivee D03, and was wondering if installing a custom pickguard and maybe even arm rest, would affect the sound negatively at all?
The arm rest won't hurt the sound at all. The pickguard won't change things much but just remember the bigger the pickguard the more negative impact it will have on the tone. Some people can't hear a difference from one pickguard to another, but for other people it really stands out.
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thanks, so i'm guessing the heavier the pickguard, the more difference you'll hear in the sound

a few pickguards i'm looking at are made of rosewood (they're about 2mm thick), which would probably be considerably heavier than a tortise pickguard, i'm left to assume the rosewood pickguards would affect the sound of the guitar a bit much?
Yes and no. Rosewood will be heavier and will change the tone more than a tortise pickguard but wood will also change the tone in a different way. Some people like the way a wood pickguard sounds and others think they dampen the tone and don't like them so it's still up to personal preferance.

I tend to like the cheapest pickguard I can find because they also tend to be the thinnest and the lightest. Why spent $30 to $50 for a tor-tis pickguard when the cheap lmi pickguards that are almost the same color only cost $4 to $8
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