i just want to make extra sure i can use velas manor as a house and store things there after completing "the summoner" in tribunal.

there are atleast six chests, three small, three large... as well as a dresser and closet.

that place would be very nice to have, so im hoping someone can confirm this for me.

I've been using http://www.uesp.net/wiki/Tribunal:Godsreach#Velas_Manor over and over again without losing stuff in there or having a bounty on my head if that worries you, so it should be safe unless you're mods that changes it.