I'm 1000000000000000000000% sure 五十嵐 is read as igarashi. Did you get it confused with 五十鈴 (isuzu)?
edit: was the translator on drugs while doing the last panel?
"the two of them haven't even married, let alone going out", it should be the opposite.
kaede says "her boyfriend, her husband, grandchild" and referring to that seizou says "come on great-grandson, let me see them soon" which doesn't make any sense at all no matter how you see it. In the raws, seizou says "早くひ孫見せてけろ" which translates to show me 'em great-grandchildren soon.
Other than that I liked this release more than the one done by the other group.
edit 2: found this link to 五十嵐 family name article https://ja.wikipedia.org/wiki/五十嵐