Water on the garage floor could be fixed by adding a mini speed bump under the garage door. Paint a strip of aluminum roof sealant against the wood where it touches the floor for a trick garage look. What, $500 if you pay somebody?
Warped and loose siding - I guess vinyl? - can be fixed by climbing a ladder and snapping it back into its grooves. Worst case, put a painted aluminum nail through persistent loose / mis-spaced spots - but only one nail per piece so it can still expand/contract in both directions. Really worst case, reside the whole wall yourself in about 2 weekends and $400 in materials, making sure to space the pieces correctly this time.
The biggest issue, attic mold, is 100% due to a lack of vents or a bathroom/stove fan venting directly into the attic and causing humidity, which condenses on the cold underside of your roof at night. Surely your inspector would have noticed the later, so add vents. Roof whirly vents are about $30 a piece. Also check for soffit ventilation being blocked by insulation. With proper venting the mold will die from a lack of condensation on the bottom of the roof decking. The stain will remain for the next inspector to freak about, though. Personally, I'd leave the dead mold alone - once it's dead of course. It's not in your living space and the dead, dry stain isn't putting off spores. The wood itself is perfectly strong unless it's a full on leak we're discussing.