Coast to coast trip by bicycle

Hello everyone !

I'm planning coast to coast trip by bicycle. It will be between beg-mid of september to beg-mid of october.
I have some questions and i'd like to get some info about.

1. Do the weather in my dates fit to trip like that ?
2. Do there is common route to do coast to coast trip by bicycle in Ireland?
3. How much days its took to me to finish it (approximately)?
4. There is hiring bicycle that i could to return back the bicycle in the end point area/ i must to buy bicycle / someone has advice what recomended to do ?

I'd like to get any relevant info about!

Anyway thank u
Bar