The forgetmenot seeds sounds a lovely idea. I planted some in Charlie's flower bed burial place - but they do grown incredibly tall, being wildflowers. A memorial plant that is easier to maintain and longer lasting might be a nice idea
Not silly at all re the Strawberry house. Some things I could never use again - for a long time. And couldn't use Charlie's house again or his rainbow bridge. But in time some things have been washed and used again for our current hamster and have taken on new memories.