Unsure about fostering

My husband and I have talked about becoming a foster parent since our oldest daughter, now nine, was a baby. We both come from large families that had ample love to go around so the idea of helping a child who wasn't as fortunate has always appealed to us. We wanted to even possibility take in multiple siblings because we know they are harder to place and for someone to have everything turned upside down the last thing they need is to be separated and had even discussed the possibility of adoption. Were currently in the process of putting a house on our land and will finally have ample room to do what we've talked about but after researching it a bit more I've become hesitant. I know it's not all rainbow and sunshine. Kids in foster care are there for a reason and can have problems making things difficult particularly in the case of trust and/or behavior problems. I am a very patient person and I work from home so I have nothing but time so that part I'm not hesitant about. I am very organized person who appreciates structure. My kids have a schedule they follow and a chart of chores they are required to do. My husband is a professional driver who is gone for weeks at a time so they help me on the farm taking care of a multitude of animals from cattle to chickens. For a child/children who may not be used to something like that would it do more harm than good? I would never expected them to come in and immediately follow these rules, my children have done it their entire lives and still don't half the time. Still, everyone in my house is expected to pitch in but I would never want to push a child from a difficult background too hard and I'm not really sure how to approach that. And is it okay for biological children and foster children to share a room? I know the room requirements for that and ours well meet that the rooms being 15x14 but is there potential problems arising from that? Jealousy from either one? Fighting beside the normal sibling/ children not getting along at a particular time? The last thing I want is to creat any problems for any of the children. I know the whole boys bunk with boys and girls with girls which works since I have a girl and a boy. Both my kids have been spoken too about this is length and though I've explained it's temporary they are very excited to another brother and/or sister. I've also read it's not the best to get kids older than your own and with my youngest being six that is a narrow range I just want to make sure my own children and any I take in fell safe and secure. Another is I do have a disabled family member living with me. My mother in law has a MS and though she is still fully independent her mind completely sound and even comes and goes as she pleases she is unstable on her feet and is prone to fall. This is something my kids are well use to including being her legs at times she is unable to walk. My concern is in the case of a child being potentially violent. She is physical incapable of defending herself if it ever came to that and I wouldn't want to put her in a position that could result in injury. Any advice is greatly appreciated.