TOPIC: "Book an Inspection" section

A few questions for Dominic;
In the "Book an Inspection" section, the Form components edit area has boxes with field length, width and height.  What is the default size?  
Maxlength of the textfield.
Width of the textfield. Leaving blank will use the default size.
Height of the textfield. Leaving blank will use the default size.

(Why should there be a maximum size other than for a phone number or something like that?)

In the webform mail settings area there are some sentences I don't understand;
After adding components to this form any email, select, or hidden form element may be selected as the sender's name for e-mails.
Two more sentences have textfield instead of email.  What does this mean?
Thanks

The defaults vary by theme as some are one column, some are two. So there's no one answer.

Some people want a maximum in comment areas if they want to limit people to a few short comments. You could limit zip code and other things too, but most people don't bother.

That last one looks like a typo.