Question
When I google for my zone it says 7, 7b, or 8 depending on the site I use.

I don't know what to do about these aggravating little rose plants I have.  We planted them about 5 or 6 years ago.  I don't remember the type, but I am pretty sure they said miniature roses.  I thought that'd be cute growing out front.  I was wrong.

There are 3 remaining of the five plants.  The final three keep getting leaf disease (for which the local garden place gave us stuff to use for that).  The roses that do bloom, if I'm lucky enough for that, are maybe one on the whole plant all season.  The one plant had 3 or 4 roses this year, one per stick.  Now the one looks dead, but I think it's still alive barely.  Another looks almost dead, and the last just looks pathetic.  None have leaves, and I'm afraid that their funky leaf issues will transmit to the other rose plant I have.

We also have a large ballerina 1937 type shrub, which is doing great.  Looks a bit scraggly this week after all the heat last week, but it was great through spring and summer.

We hate to dig these pathetic little ones out if they have potential to be really great!  They are still only about 2 foot tall.  Which was about what they were when we planted them.   I'm about ready to dig them out and get new ones in the spring, but thought I'd come ask if these little plants have any chance of being great haha

They're all grown in a shady area.  They get sun later in the day, but for the most part it's under the shade of the roof eaves.  When we moved into the house, it didn't occur to us to watch the sun for a few days before planting things.

Is my best bet just to dig the plants and roots out and start with another type of roses?

Answer
Before you dig them out just get mad.  From your description, it sounds like they aren't getting at least 6 hours of full sun and may be in soil that has cement from the foundation creating poor soil conditions. Mini roses will usually not tolerate too much shade. One of the satisfactions of dealing with a rose you are thinking of getting rid of is that you learn a lot on how much abuse a rose plant will take.
I would cut all the minis right back to 6 inches as you have enough time in your zone for them to grow back again. Scatter a small handful of whatever fertilizer you use on them, water extremely well so the soil is literally soaking and then place a mulch all around the base. Roses love cool damp roots and hate dry hot ones.If they are going to survive where they are then that routine should tell you whether or not it is the situation they are in that is making them grow and look poor. Roses which are growing well can usually live with some black spot on their leaves but if they are struggling then the fungal disease will stunt them.
If all fails then I would move them into full sun and repeat the same routine. Keep in mind that you can cut a rose right back to a few inches and this quite often will rejuvenate it. Of course it has to have the vigour to grow back again but if you were going to get rid of it anyway, then it is interesting to see how quickly they recoup and throw out basal canes.
I also would cut back your Ballerina and tidy it up. When a rose has done well and then looks straggly, it is usually because it is having trouble supporting a lot of growth in the summer heat. I have just finished whacking back my roses so they won't fall back, as it is now hot and dry and I am on a well. Hope this helps.