Although it sounds like your HL has more issues than just the water.
The water issue sounds like my Dodge Caravan. When rain runs down the windshield it enters in the "cowl" area that has two drains with short length hoses (1 on either side) that direct the water thru the engine compartment and away. These drains and hoses can get clogged from pieces of leaves, dirt, etc. When they get clogged the water will spill over into the passenger side floor. On they Caravan they are easy to clean and I do it on a regular basis. Perhaps the HL suffers from the same issue. As for the lights???
Ken
The water issue sounds like my Dodge Caravan. When rain runs down the windshield it enters in the "cowl" area that has two drains with short length hoses (1 on either side) that direct the water thru the engine compartment and away. These drains and hoses can get clogged from pieces of leaves, dirt, etc. When they get clogged the water will spill over into the passenger side floor. On they Caravan they are easy to clean and I do it on a regular basis. Perhaps the HL suffers from the same issue. As for the lights???
Ken