Multiple Regression Guidance

Hey all! Wondering how many experienced multiple regression enjoyers there are out there. I'm pretty new in general and have typically relied on paired sales, median sale price stuff, etc but I got a buddy that teaches statistics and showed me the ropes on MR. I love it so far but have so many questions and his knowledge unfortunately doesn't extend into the realm of Appraising.

For those of you who use it, how do you personally apply it? Assuming your Pvalue, StD, and Rsquare looks good, do you just adjust by the coefficient? What do you do in situations where the adjustment is better suited proportionally? Do you divide the coefficient into the median sale price of your sample to get a percentage or something?

What do you do in situations where the MR disagrees with our other analyses? Would it be reasonable to account/adjust these factors in the sale prices prior to the MR analysis? Things like garages and bathrooms always seem to throw the Pvalues, despite having multiple paired sales/median sale price justification. Should I instead take that to mean things like garages/bathrooms don't impact marketability as much as I've previously thought?

And finally, how do you go about presenting the data in your report? There are a variety of factors which don't make sense as a line plot. Would I just put the P-Value, StD, Rsquare, sources, etc plus my conclusions into a PDF and tack it on in there? Let's say my conclusions jive with the second half of my third paragraph and I realize these factors don't impact marketability or a statistical relationship cannot be established. Can I put the high P-Value/high StD/Low RSquare into the report as justification for lack of adjustment as well?

Obviously I need to take a class specifically on how multiple regression is applicable as an Appraiser but if any of you are generous enough to share your experience or guidance I'd be forever grateful. I just want the make the strongest reports I can. Thank you