Range of 24 to 78 inches is more limited than I would want to have, but you should try it for a while to see if you are happy with it. If you find that you want more on the high end, you can always put some of your other chainrings back on it.

I have a range of 19 to 122 inches. Unladen around town, I spend about 90 percent of my time in the 60 to 90 gear inch range. Hauling a lot of weight, I would probably be in the 50 to 80 inch range most of the time, but it would vary greatly for the terrain where I am biking. But, I am in a gear in the 20 to 30 inch range on the steeper hills so even though I spend very little time in those low gears, the low gears are critical to have available. While I can climb a 7 percent grade with a 30 inch gear, I am breathing pretty hard at the top of the hill with that gear. I find a 20 inch gear a lot more relaxing to use on that type of hill on a long day in the saddle.

Regarding 24t front, if you can find one at a good price and have the tools to install it, go for it. But having a 26t on the front already is pretty close to the 24t so I would not recommend that you make that change unless it is easy, cheap and convenient. You can decide later to make that change.

Your rear derailleur might not handle more than 28 teeth on the cluster, so if you go for a bigger sprocket in the back, you might need a derailleur too.