I think you have to interpret well what type of customization to perform, at first glance I think there are two types:
The playful customization pursues a pleasant relationship between the user and the interface according to their aesthetic preferences or comfort in use. As a non-essential alternative option, the user has more time to ...
I am not going to tell you which one to pick, because I think it really needs to be a decision you make yourself based on your target audience. However, I will provide some suggestions to help remove your concerns to each option and hopefully help with your decision.
Focus your selection based on the type of data your users will be working with. ...
Maybe you can think about having an edit state for the whole grid?
If you click that icon the whole grid goes into edit mode and the user can edit the whole grid in one go. It depends if that is a common user behavior or not.
Some of our apps have a "hover the row to see the applicable icons" and other apps have a "all icons are visible because the user typically needs to know all of the info they represent"
I'd say your choice is going to come down to striving for no-visual-clutter vs really needing to know what info the icon conveys beyond what action it ...
I would say, if it works for your users, then stick with it.
Option 1: icons everywhere
More clear that all rows can be changed. Introduces a lot of redundance and visual clutter.
Option 2: icons only on selected row
Not entirely clear that each row can be changed. Visually less redundant.
According to the Universal Principles of Design book, this falls under the Constraint principle, more specifically, this is a combination of a symbol and convention constraint:
Psychological constraints limit the range of possible actions by
leveraging the way people perceive and think about the world. The
three kinds of psychological constraints are ...
Judging by the context of the title bar, this seems to be a modal-type interface. When the user hits "send", you should wait until confirmation that the message has been sent. If it was, close the modal (and hide the keyboard) and add a small alert that it was successfully sent. The closing of the dialog signals to the user that something has ...
I like the way WhatsApp resolves this:
I think it's in the user's mental model when the color changes then it means "READ" so I would do it the other way around: from light grey to dark grey, or better change the color to green or blue to be even more explicit and you make sure something happened there. I think it's ...
Ask yourself question what the icons are used for. If they have a simple informing character they might need to fit with your text. (example: external link)
On the other hand, an interactive icon used for navigation should be bigger to make it easier to tap with your fingers and to give a clear incentive.
Some more interesting thoughts:
you could ...