A better movie for this topic is "Pacific Heights", where Michael Keaton's character makes a rent pre-payment (and engages in some disturbing behavior as well).

Ironic that your website states "Please do not disturb the tenants"  AND "showings by appointment only"  LOL!

When I’m not working ; the business cell stays on silent so I’m able to spend time with my children without being disturbed.

I find that figure disturbing.

"I'm sorry to disturb you, you may not be the right person for this

If you have the stomach for it, it's a very rewarding business but sometimes it can be scary, disturbing, challenging & sometimes down right disgusting.ENJOY!

We're also lucky that none of the bedrooms share a wall so that should reduce any noise disturbances.

Google voice them with "Do not disturb" enabled.

The biggest piece to closing on something off-market is being able to have an offer presented to avoid the hassle of listing- especially when there are tenants in place that do not want to be disturbed. 

in affected areas first.Taking out drywall is also fairly easy (big hammer, regular hammer, and flat prybar is about all you need) but is very messy so enclose the work area, wear protection and ventilate it.Note if if this is a pre 1978 house which it looks like it is,   and you plan to rent it,  then legally speaking you must be lead paint certified and follow abatement procedures when removing or disturbing more than six square feet of painted surface in any room.