You're actually going the wrong way with your kerning. Kerning is not the proper distance between letters based on where a letter ends, but the proper eye spacing to make words more legible and eye appealing to look at due to the body/stroke of the actual letter, not based on the serif. When using a letter, such as you picked, the serif sometimes will overlap or join to make this clunky appearance go away. Another reason, to use upper and lower case. As in another thread, certain serif letters don't work well, when using all caps. This is more of a decorative style letter, and not meant to be a headline type face, regardless of the size of the sign. Being a designer, even if the customer likes it, you need to know where to interject good balance for copy, color combinations and letter weight. 7" letters can be seen at about 400' without any handicapped styles. Your thick/thin style will be lucky if it's readable from 150'.
Like you said, they're happy, so you are too, but once that baby is up, be prepared for people to say....... I can't read it from the road or whatever the viewing distance is. Don't come back with....... well, you said you liked it. They will say, you are the professional here, not us. Do a squint test. Print the sign out in color on an 8.5 x 11 and stand across the room and see if you can read it, within 2 seconds. Since you know what it says, have someone else take 2 seconds to read it and tell you what it says.