yea id do away with the foil ,it can cuase burn spots too,
white walls do a great job paint the walls gloss white will bounce the light very well and evenly but all in all your on the right track
you try
you seek advice
and willing to listen so i will say this do not give up and learn from any mistake
and you will make them even pro's do
im a outdoor grower and only start them inside for the most part
i have some them self ballist type Floro's in a cabnet i use for starting them out some
read up all you can and apply what fits your situation
good luck peace