I pasken that I remember hearing some prohibition on asara bteves. I further pasken I may be wrong.
and as far as the Spanish expulsion, I think the Rabbonim permittted it for those TWO reasons. Because they were going Al Kiddush HaShem, they permitted it in order to lift their spirits. (I don’t remember a pikuach nefesh factor) And I think it wasn’t the Abarbanel who was the one who permitted it, rather the general Rabbinic presence.
(drawing on memory), again I pasken I may be wrong.