Re: male + filter -- The filter flow might still be a tad high for him and his floofy fins (two of my males cannot stand any flow at all, it's a PITA). If you check out the guides to baffling filters (it's easy!) in the stickies on betta care, you'll see it's not hard to do, and your fish will probably enjoy a lower flow. I have taken to using sponge filters of late, and they are brilliant if you use a flow valve on the airline.
Females are awesome. Mine likes a slightly higher flow (smaller fins) and is totally a darling to interact with. Glad you're enjoying yours.
Re the feeder thing - No. Get some high quality pellets and feed small amounts twice a day. If you are away fr a weekend, your bettas are better off not eating than having food mussing up their tank constantly. If you're away for longer, try to have someone with a brain come round to feed them once a day (a brain is important, people do such dumb things around fish).
Your temp's a little low still but not awful, don't panic. I use dymax adjustable heaters and swear by them, and you will find adjustable sooo much better. But if the budget's tight, and it's not freezing where you are, it can wait, IMO.
I had to giggle a bit at "my wife just wanted simple fish in a bowl".. no such thing, there really isn't, not if you care about your pets. But what you will find is that these little guys in a good, appropriate environment will repay you 100 fold, in the enjoyment they bring.
I have spent hundreds and hundreds on mine, over time, and I am a sole, disabled parent on a fixed income. I just get things as I can afford them, here and there, and look for bargains. I do without the hairdresser, nails done (who wants to put fancy nails in a fish tank anyway? lol). I'd rather enjoy my fish and do without the fripperies of life, if it comes to it.
For plants --- good idea is to join a fish forum that has a lot of members local to you and ask if anyone's selling easy-care, low-tech plants. You will find people quite generous usually, and it works out wayyy cheaper than buying from a store (and you won't get non-aquatic plants...stores can be bad that way).