Here's some answers to your questions, I hope you find them useful.
SPAM PROTECTION - can be done as easily. Select the form you want from Form Manager, then click Form Properties (near top right of the screen)in Form Editor.
Click the check-box the box further down the screen Turn on Spam Protection (CAPTCHA)
Save the form.
From Form Manager, click View Form and Machform will load a functioning view of your form and you will see it with the Captcha code feature included - automatically generates the code to be typed in and includes the field to type the code.he code already generated and a field to type in the code.
**The only other thing to do is check with your host that the "GD Extension" (for PHP) component is installed/enabled on your hosting server.**
PASSWORD PROTECTING A FORM can be done by clicking Form Properties in the Form Editor and then click the check-box labeled Turn on Password Protection.
You then set a password in the field which appears after checking the "turn on" box. All users must know that password (and only that password) to use the form. Machform provides the basic password protection - it can't be done in the way you're asking with registered users loggin on to use the form etc as with this forum.
You'd need a membership/user management solution for that, and I'm not sure how integrating it into Machform would work.
CHANGING FORM PAGE STYLES is done through the CSS file for that particular form.
If you're not familiar with CSS it might be a bit difficult, but this forum is very helpful and Yuniar or other members will no doubt give you some very useful tips.
SUCCESS MESSAGE - add a "Thank you message by clicking Form Properties and then further down the page select the option Show Text and type in a short thank you message.
You can alternatively create a redirection to another web page with the "thank you message" - although this can be a redirection to any page in your site.
** Just curious -- if you did remove the "edit form", "edit Css" etc, how do you expect to actually edit the forms if you need to change them?
They have to be edited through the Machform editor since they are linked to the server hosting the Machform software, and generated from a MySQL database "on the fly" They are not pages residing on the server as such.
If you want a run-down on all the features, then read this page:
http://www.appnitro.com/machform/version2_whats_new