Weeks 7-8 are the hardest. You're exhausted and full of self doubt and frustrated. Some part of you feels like you should know what you're doing by now and that you're not doing it well. Many negative emotions. It's part of the process. :/
I know what you mean about looking over at boys and I just remind myself that most guys can trip over weights and they'll put on muscle.
Who says 45# on FS is light? That's fantastic!
Height of the bar on DLs is a legitimate issue. I used to stack some plates to get the bar the right height until I found a gym with bumper plates.
My RDLs and DLs are usually around the same.
Don't do cardio right after lifting: they're two opposing metabolic states and you'll get sub-optimal results. In a "perfect" week I did cardio on Tuesday and Thursday evenings and then on Saturday and lifted M-F in the morning.
7x week? ALWAYS take a day off. It's important.
Cardio got fun when I started to get really creative with my routines about 6 months in. The Cardio Sucks book and exrx.net were really great for ideas. I posted a lot of my HIIT workouts here.
It's not easy to cultivate the practice of bodybuilding. But guess what? You're doing Awesome!
It's been fun sharing this info with you. Keep up the great work!