Smells, leaks and electrical issues without wiring diagrams are impossible to for anyone to diagnose on the internet, unless there is a recurring boat-specific problem that is a known issue, like aluminum framed fixed portlights.
I wish you luck, but in general most skippers have found the solution by being patient and doing all the usual diagnostic things, like spending a LOT of time on the issue.
You said you replaced the hoses. Many times new hose clamps loosen shortly after installation, and need to be snugged up. If you have PEX or similar lines, check all the joints. Is your galley drain leaking under the sink? What's above where you found the water?