Does shifting in an automatic damage the car?

My car (Honda pilot 2011) has a 1/2/3 setting on the car and if I use that while driving will I damage anything? I typically use it when I'm driving for fun and shift it at red line and then shift it back into drive at the end of 3rd gear. My old car was a stick and I miss it but will it hurt the car besides the normal wear and tear?

Shifting manually in an automatic transmission will not cause excessive wear and tear… Unless you constantly over-rev the engine while playing with it this way (i.e. Shifting at the 'red-line'… It's not there for a shifting point). However, understand that automatic transmissions will downshift on their own when slowing down. It's designed to downshift when the speed gets below a certain speed.

So go ahead, enjoy manually shifting up. Just don't downshift manually. Doing so too soon can also over-rev the engine and can cause internal components to wear prematurely (e.g. Valve guides).

No it is not true.

I do hope you did not shift your manual at the red line.
Even racing drivers for not do this and they do not worry about repair costs.
You can control the shifting on an automatic by using the gas pedal sensitively.

During normal driving shifting using the 1/2/3 is no problem. The transmission is designed to do that.
However, driving at the red line is idiotic at several levels. Get a shift wrong, just once, and you can wreck the transmission. If you're red lining you're not drivine safely on a PUBLIC ROAD. Staying near the red line does the engine no good at all.

As long as you don't downshift at too high an rpm that you red line the motor you're fine.

You're not damaging anything by manually shifting an automatic trans like you describe. The engine is designed to safely be run all the way up to its redline RPM (… That's why there's a redline RPM) and the engine/trans have computer controlled safeguards incorporated that will prevent the driver from doing anything ill-advised enough to damage the engine or transmission whilst shifting the transmission manually.

For example, the computers controlling everything won't let you execute a downshift to 1st at a high enough speed to exceed engine redline RPM (so no worries about accidentally downshifting into ~1st @ 55mph for example - even if you tried that on purpose, the computer wouldn't actually execute the downshift), nor will the computers allow you to overrev the engine past redline RPM if you happen to fail to call for an upshift in time with your right foot planted to the floor. If this were a much older car where things like transmission shifts and engine redline were not computer controlled/regulated, you might be able to do something idiotic and damage the engine/transmission, but your car is more than new enough to have computer controlled safeguards in place to prevent exactly that sort of thing. So in other words, no worries about having some fun.

You won't be doing damage, but you are wasting gas running that high of rpm's.

Redlining a Pilot? Geeze. Downshifting a lot can cause wear to the clutches.

If the manufacturer thought it would damage the car they would not give you the option to do so.

The value of that is to hold the transmission in a lower gear and prevent the constant up and down shifting on mountain roads. In other uses, the transmission is actually more efficient if you leave it alone.