Hi Jen :)
Lots of questions (don't worry, any questions are welcome here) I'll try to answer one by one. I'm a adoptive parent of three, I don't have any birth children though
Bonding must be a number one worry people have! And i think it's always heightened when you already have a child. Adoptive parents who want to adopt a second child frequently feel the same thing. Honestly, it doesn't make a difference whether your child is adopted or biologically yours, that won't affect how much you love them. I couldn't love my kids any more than I do, and there are parents on here who do have both and would say the same.
Fanily is tougher, becuase you can't control how they feel although they would hopefully control their reactions! Hopefully family would be very on board as most of mine have been, but they aren't always. Talk to them about how they feel, but ultimately this is about you and your children, and if you are 100% committed you go ahead with or without your in-laws approval. I would say it's rare for family to treat kids differently, but it sometimes happens sadly. Some people have to make difficult decisions about whether to stay in contact with certain family members because they make life too difficult. At the end of the day, however much you love them, if they try to treat your children differently, you have to lay down the law firmly. Although, they may be over the moon about a second GC!
You do (generally) get a lot of information about a child before you agree to adopt them, but by the time you meet them you need to have committed to them fully. When they move in, they are legally foster children and adoptions are not finalised to several months at the earliest. Disruptions (ending the adoption) happen, but given the massive and probably very long lasting emotional trauma a child will go through if they are uprooted and moved to a new family, told it is forever, then sent back again, disruption is the last resort after major problems can't be solved
Bonding with your child can take a long time. Sometimes people find it's 'love at first sight', but others don't, and that's normal as well. After all, when you give birth to a child, you nurture them for 9 months before even meeting them and have a while to become comfortable with the idea of a baby, whereas adoption generally involves an older child with a formed personality, previous trauma which impacts how they function, and no bond to you, coming into life with little to no adjustment period!! We had a thread on bonding recently, here which you might want to read
Lastly, agencies will want a two year age gap at minimum between your son and new child, and some will want more than 3 years gap. Realistically, you may not be able to start the process until your son is 4-6, as you have to be approved for children at least 2 year younger, so if your son was 5 when you were approved you would be looking for a child 0-3 and so on
There are quite a few babies avaiable afor adoption though, and plenty of poeple adopt children aged under 2
Hope that helps, ask any other questions you like