I kind of agree with you here, this coule is one of my favourites, although I think Aden didn't really know the 'old' Belle. I don't think Aden really understood what type of person Belle was like when she was a teenager. I do think that Aden knows the "changed" Belle we see, the mature 20 year old. I guess we're to assume they have had disucssions with each other about what they were like as younger teenagers. So to a certain degree I agree with you..
If you take a really good look at their relationship I would probably say Aden did love Belle a little more than Belle loved him, but I guess that's because Aden hasn't had many people in his life he has loved and who have offered to love him back. So maybe he is more grateful in that way? But that doesn't mean Belle does love him alot.
I don't think that Todd and Jess portrayed hot, steamy chemistry, sorry I love you both Jess and Todd and I love Adelle, but I really didn't see any chemistry. I did however see lots of affection and love portrayed which was lovely