It is a purely personal decision how you structure your child's interactions with you, sleep and so on, but the sentence that stands out for me is
'Somewhere there is a big sheet with lots of red crosses on '
No there really isnt.All there is is you, your family, your (still very very tiny baby) and what works for you.
I wonder if you have been hearing alot from the the 'rod for your own back' brigade. I really wish I hadnt listened to them with DD1, I felt guilty for feeding her to sleep, having her in my bed, carrying her all the time, not leaving her to cry. All the things that I now realised were actually my way of doing things, I felt bad about, and that affected my enjoyment of her early months.
With DD2 I held her as much as she wanted, slept with her, breast fed her to sleep, the lot. I loved it loved it loved it because I had enough confidence to realise this was actually how I wanted to parent, and that long term it would be absolutely fine. It took a few weeks of gently trying her in the moses basket before she would settle there but she did in the end, and I never left her to cry.
I have coslept lots without problems incidently, its your own judgement of course and there are guidelines, but there is another viewpoint than the one you seem to be hearing.
If you are enjoying the things you are worried about, please keep doing them, they are in fact your way of mothering. Your Ds is going to have to get used to you not being able to do all the things he is used to just for while, and it is hard for him, but it is the one short term down side of what will hopefully be a very benefical life long sibling relationship.
I found bunging the new born in a sling and getting on with normal stuff with DD1 worked pretty well.
Hope all goes well.