Concerns:
I have lots of brown edges in the leaves and curling leaves – it had some brown edges when I purchased it.

Darryl’s Analysis
Environment:
The current location where you have it is great in terms of light.
Effort:
Your watering strategy sounds good. It’s good to occasionally flush the soil so excess water that drains through can leach away built up minerals. IMPORTANT: although this flushes out built up minerals, it also flushes out nutrients so be sure to keep up with fertilizing (it sounds like you have been). And remember that this only minimizes the brown patches – you can never completely prevent it!
Expectations:
Your Bird of Paradise plant looks completely within normal parameters to me.
The reality is older leaves will eventually get blemishes or yellow and will fall off by no fault of yours. Browning and leaf rips can never be reversed or completely prevented. As long as the overall plant is healthy and growing in the right light (which yours seems like it is), then you can enjoy the overall plant even if a few leaves die off here and there. Don’t let perfectionism ruin your plant journey!
If you want to learn a healthy, balanced approach to houseplant care, check out my online course or my book.