Things which render the Salaah Makrooh

Q: When arranging the row for prayer I saw that one man had a trouser with a PUMA logo (animation of a jaguar) at the side of the leg, so I did not stand next to him, but I stood next to the person who was standing next to him so that this animated picture would be not visible to me. However when we stood up for the 2nd rakah the man was for some seconds still in the sajdah posture so I saw this animated picture. Did my salaah become makruh and must I repeat it?

Q:

1. What is the status of Salaah performed with short sleeves (shirts/kurtas)?

2. What is the reason for it being makrooh?

I heard that Nabi (Sallallahu Alayhi Wasallam's) under arm or to the effect became visible while in salaah due to the sleeves being broad or wide. The portion above the elbow became visible as with short sleeves.

Q: What is the ruling regarding performing salaah with short sleeves or a T-Shirt? 

Q: Should one fold his pants in order to expose his ankles at the time of Salaah?