I think there are several issues here but the only one I want to comment on is school collection. Our birth dd (possibly with ASD) could manage one day at after school club.
When we upped it to 2 she was not happy and it went back to one.
After school club is not home, yes it is games and sofas instead of hard chairs and work, but it is not being at home.
Going to Grandma's house or whoever's home may come to feel like home but it stilll is not.
And actually building attachment with any child, especially an older one, you really do not want Grandma's house to feel like home! You want your new child to know one home and one or two parents.
The post school pick up is where you may hear about problems, or bullying, or achievement or delight. Two or three hours later you may not hear this.
Our adopted son came to us at 3, went to school the followling year and is now 7.
About once a month a friend collects him and he handles this fine as the friend is great and actually going there is a treat.
I suggested after school club one day a week recently and got a firm no. So far he has resisted all but two after school activities. And these were each just for a term or half a term ending around 4.15.
For several years (maybe 2) he left school and found some reason to burst into tears. The pressure of school (and he is bright with no learning difficulties) made coming home (changing from being at school to bring at home) a tense time.
You seem to be offering this child a new life as your child which is fabulous. But please do read up on what is important
My kids love holidays and treats BUT they absolutely value their own space and time at home and so I work school hours (and some time in the late evening or weekend) and dh works full time.
It is not that they need me to be constantly talking etc. Today my son said 'warm me up' and I sat on the sofa and held his hand. I fell asleep! But I still feel that the physical presence of being in the house (his house) with me (his mum) is a kind of 'balm' and as he gets older he will need it less.
He is young for 7 and I think this child may be young for 9 so be prepared for small things to matter.
Good luck.