Don't delete architectures
If I were you, I'd back up and then re-install your OS without languages etc, then run XSlimmer after installing apps. Longer, but better and safer.
I successfully used Monolingual on Tiger last year with my new MBP. I only removed languages -- and I was very careful about selecting what was removed. The Monolingual defaults looked like they would have removed English and made my Mac unusable -- I don't understand its defaults, but I think you need carefully review them as they can't be trusted.
I've not tried it since upgrading to Leopard; I didn't know if there were any incompatibilities introduced since then, as Monolingual hasn't been updated specifically for 10.5.
Thanks but have now decided to not to risk things going tits up & dont want to
go threw backing stuff up to save what might be just a couple of gb's
I used it on leopard no problem and saved a few gigs. Not a big deal to some, but on a 250 GB MBP with a 130+ GB iTunes library and a 30+ GB Parallels file, a few gigs comes to be a big deal.