Besides my previous suggestion about tank venting, it seems possible that your friends thought about the fuel pump could be a good one. On my boat, the fuel tank placement is mostly above the engine and I can get gravity feed to the carb even when the fuel pump failed, however it may not be enough flow. You can do a rough check without a gauge by removing the outlet hose from the pump and puting it in a can then operating the pump to visually check flow. It may gravity feed slowly and then flow faster when you start the pump. If not, the pump has failed.

Since you seem inclined toward upgrades, I highly recommend the electronic ignition kit from Indigo Electronics. While your points and condenser sound ok, it's nice not to have to worry about them.