I don't have a Forester, but here's a couple tips:
If it's low flow at a particular faucet, you may have either a flow restrictor or debris clogging the aerator. Check\clean these first as it will involve the least amount of work. Our bathroom sink had this issue and it was due to a 1/2 inch splinter of wood that fell into the plumbing lines during construction.
If it's slow on all faucets via shore\city hookup AND via pump you may have a crimp in multiple lines or one of your bypass valves may be partially open or closed. Find your water access panel and see what kind of mess you have going on where the lines come in. Check the area for one or more twisted\crimped lines, ensure all bypass valves are either fully opened or closed and see if that helps. Also check your filter while you're in there - if it's over a year old or looks awful it's probably time to change it.
If neither of the above helps, it may be warranty time unless some other folks have suggestions that I'm not thinking of.
good luck and keep us posted!
Ryan & Cortney
2012 Windjammer 3008w