Does the velcro adhesive take the paint off the door when it is removed?

Velcro has very strong glue and, according to our customer's experiences, depending on the surface, it may come off with the paint. In case of removing the velcro, we recommend heating it first with ex. hairdryer. The glue should melt a little bit and be easier to remove leaving no residue on the surface nor removing the paint.

Will this work on a screen door?

Yes, our door protector works fine on a screen door

I'm trying to protect my kitchen door into the garage. It says this is flexible enough to cover trim, will it work for an outward opening door?

Actually they have another product that hangs around the doorknob that would work better. We purchased it for the same reason. We renovated our interior and was working in the garage and our dog would scratch the door frame and door when she wanted out. You can trim to size. Look for the one that hangs from the door knob. We used this product for the back deck to the back yard to keep her from scratching up the door. However, you can cut this product you are viewing and use 3M on the door frame and the remaining on the door.

How big is the packing? thanks

Our scratch protectors are packed in the PE bag, so the product package is flat 35 x 15 x 0.15". However, we do not know the carton size Amazon ships our products in. We received messages from our customers claiming shipping boxes are oversized, so we reported that to Amazon a couple of times. Unfortunately as far as we know nothing has changed in this matter.