Ok, 1st the backsplash question....... I really don't know much about the installation process, but I do know that if done correctly it can look just like real tile. My friend has it and it looks great.
2nd question.......... your 10 month old playing with the 3 yr old who has Autism?? Why do you think the child is Autistic? Autism does not make a child "slow" it effects more of their social skills, and this child may have other issues. He could have some serious behavior problems if he is playing to roughly with your baby. That being said, autistic children DO have social issues and may not know the appropriate way to play with ANYONE, let alone a baby, and should NEVER be allowed to play unsupervised with a 10 month old child. It will only take 1 time for that 3 yr old to fall the wrong way on your child and cause severe damage or death. I hate to sound so negative, but after running a liscenced preschool/ home daycare in Massachusetts for over 11 years I would have never have let any of my 3 yr olds play with the under ones for their "free play" time anyway. There were too many possible types of injuries, as well as too many toys that the 3 yr olds had that the 10 month old really shouldn't be allowed to play with. If the person caring for your child does not have anyone else to help her with the children, then she needs to keep the 2 kids from playing "rough" together when she is right there, and if she needs to leave the room for the bathroom, to prepare food, etc she should either bring your child or put the 10 month old in a safe place such as a playpen or a high chair with a few toys, etc (just for a few minutes not a long time) so she can use the bathroom, etc. I am going to assume that these are not the only 2 children that she is caring for during the day, and that the 3 yr old has other kids to interact with. She should also be trying to teach this child the appropriate way to interact with his peers, no matter what the child's diagnoses may be. All children need to learn how to play together, regardless of whatever obstacles they have in their own lives. To not teach them is to do them a great disservice. If you are not able to communicate your concerns to your child care provider, or she is unable to change her way of caring for your 10 month old, I would start looking for alternate care asap. You really don't want to regret not doing something if your child ends up getting hurt. Good luck!