Handyy, can you please check whether this is correct? There are some things I wasn't sure of.. the first sentence, is it appropriate to add 'in your life'? Or should it be 'did you change at all?'
And 'I'd really like to be with you' sounds little bit as if he's flirting with her, do you think it's better to translate it in a different way? Maybe with 'I'd really like to see you' or something?
hmmm... the first two sentences can be translated in lots of ways, and yours is one of them. So, nothing is wrong with their meaning, I think.
But there are something to be edited:
Congratulations. May God give you a long lasting marriage/May you have a long lasting marriage. Wish you happiness/Best wishes.
I wish you had been here so that we could have celebrated all together. I really wanted to be by your side. Though, we (could/will) celebrate it again when you come.