I'm thinking of using a destruction/conjurer/heavy armored character, but does armor type have any effect on spellcasting?

Appreciate your help!

EDIT: I just found out that it effects manaregeneration and nothing more. Is this correct?

shameful bump

Yes armor does effect spellcasting. Mainly the regeneration of your magic bar as well as some damage I believe.
If you are going to focus on destruction it may actually be detrimental to wear even light armor (depending on how much magic focused you are).

Alteration provides all the armor a mage needs (especially with the "mage armor" perks) and if you don't expect to be waiting around a lot for your magic bar to refill as well as not causing as much damage.

If you are going to make a split character I recommend light. If your going all mage alteration and some robes is by far the best option.

Alteration actually provides really decent protection especially with the mage armor perks. That added with your destruction spells and other spells and buff to damage and magic regeneration is a pretty convincing case to just throw away armor all together if you are going strong magic based.

In Oblivion, it also affected your spell effectiveness (damage and duration of your spell) I think. It is listed as %.

No armor: 100% effectiveness
Iron Armor: 83% effectiveness

Something like that.

Well so far (I'm playing a pure spell caster) robes and robe helms give magika amount and magika regeneration boosts. So seems like robes make a difference quite abit for pure spell casting, You can see these effects under active effects (hit P).