It probably wouldn't be that noticeable; there's a lot of natural variation there anyway. I've longer arms and legs that would be normal for my torso; in practice it mostly just manifests in minor problems with clothes (in particular it's very hard to get a shirt that fits).
(And I expect someone both wealthy and vain enough to consider this would just get around that one with tailoring).
Don't think so. One of my friends is tall but has short legs, it's not really noticeable. You can notice it if he goes from being taller than someone sitting down to being shorter standing up, but it's not shocking, just something you'd notice if you were paying attention
Not everyone grows proportionally. Sometimes there's a condition attached such as hypochondroplasia; sometimes someone just has a longer torso than their arms and legs would suggest.
3 inches probably isn't enough to notice disproportion.
7.5cm longer tibia? Just look at your naked legs and imagine it. I think this would be very noticable.
I believe they can get 3 inches only if they lengthen femur and tibia/fibia, so it would be closer to 3.8 cm longer tibia. Still seems like it would make everything different