Nope. Maybe a SLIGHTLY higher chance of a puncture but no more chance for a blowout unless the casing threads are damaged. I always ride tires until the casing threads just start to show through the tread. Continental puts wear indicators on some of their tires and those indicators are gone just as the casing threads start to show."Acceptable" is a value judgement here.
Personally, I wouldn't ride that tire. Much higher chance of a puncture or blowout.
I fishtailed to the left, so there is some abrasion on both sides of the center, the angle of the photo may not show it. I don't have a trainer, but I did order another tire for the rear that was on sale, a single Conti GP 4 Seasons 25c just in case.The wear on the tire appears to be more on the shoulder than the top.
That's good advice. It's easier said than done, of course, but a really skilled braking technique will totally avoid that kind of skid. The rear wheel will not slide until it's almost completely unweighted as a result of front braking. A fishtailing rear wheel clearly indicates that too much braking is being done with the rear. You can practice really hard panic-type stops with the front brake alone, until you're comfortable with braking so hard the rear wheel almost lifts. That's maximum deceleration. The rear brake provides almost none of the stopping power in a proper panic stop. You brake the rear just enough so that it will start to skid a bit as a result of unweighting when you're at maximum braking level, and that helps you regulate the front brake.Consider practising hard stops so you're used to them and don't lock the rear tire so much.
I got 3,200 miles out of my rear Maxxis ReFuse. I probably could get more than that, but I ditched it when it felt thin at my last flat change. The front should last you at least twice as long.I've read that the Maxxis Re-Fuse can get up to 3k miles, my typical annual mileage. I'm not an aggressive rider and the local roads are decent, so maybe they'll last through the summer.