I am own retail properties also nationwide. I am principal broker specializing in the space for almost 20 years.
First question is to determine your properties highest and best use which may be different from it's current use. Then you have to see what zoning would approve in the area along with any association restrictions, other tenant lease restrictions, or deed restrictions that run with your property.
Then you have to do a void analysis to see saturation brand levels and tenant types for the area and what is missing and who is there and expanding, moving from current place, and just entering the market.
After you have all of that you have to make the decision if you want to sign a lease listing agreement for your property with a retail firm. We have our custom agreement and outlay expectations of what we require of them for communication and updates in advance.
You have to remember leasing brokers get paid when they close so they are often the most motivated to put whatever tenant in your property you say yes to. Not all but many act this way. So on some of our properties we use a leasing broker on our side and other time we offer a higher leasing fee total and call around to the leasing brokers to see who will bring us the best tenant we like.
The bigger the box space 20k sq feet plus in size the LONGER it takes to generally find a tenant because there are less of them looking and in a market. A bigger footprint business can often be harder to relocate than a smaller shop.
Are the buildings you own free standing or do you have smaller stores to left and right of the big box?
We do not do leasing for people my time is worth about 3,000 an hour and climbing.
The big box tenants often pay very little rent per foot because they drive foot traffic to smaller tenant connected to them or close by. If your buildings need new roof and parking lot that could be 500k to millions of dollars before the inside TI credits, leasing commissions, attorneys fees.
Good luck
