Right, TEXT-ONLY elements are not being included in the email or recorded by the DB Tracking feature.

Any input field, however, should be included in the email/tracking. If no value is given, or no checkbox checked the field should appear empty in the email.

Have you selected: "Include pre formatted form input at the bottom of …" ?

If you use fieldsets, the email should already show some form of segmentation. If that is not enough, you can de-select "Include pre formatted form input at the bottom of …" feature and build the form email completely from scratch, this would then also allow you to include the additional (text-only) elements,e.g.:

default:

A new submission (form: "{Form Name}")
=======================================
Submitted on: {Date}
Via: {Page}
By {IP} (visitor IP).

suggestion:

A new submission (form: "{Form Name}")
=======================================
Submitted on: {Date}
Via: {Page}
By {IP} (visitor IP).

============== segment 1 ================== 

field1: {field1}

…etc. 

============== segment 2 ================== 

text text text text

field2: {field2}