I like cutting paper checks to vendors and etc...I like the big black business checkbook binder, especially on the jobsite (nothing feels more like the Boss than having that check binder in hand).You can que checks to be printed in Quickbooks and then print and sign them.Or have someone else prepare, que and print the checks for you, but retain signing authority to yourself and physically control the paper checks to prevent theft of funds.You could run an A/P day every 2 weeks (or more, or less) as needed.Standard Accounts Payable precautions (bonded, etc...) should be taken if you have someone else keying them in (your CPA should be able to clarify this).With another set of eyes and hands on the cash bank account you have to be careful of embezzlement.Then just have the person paperclip the check to the invoice and stack them in a wire basket for you signature.When done signing, return them to the person for envelopes and mailing.Have your A/R person input the handwritten checks from the binder also.

It is difficult to say though based on the limited information provided what precautions you should take. 1.

Could your agent remove the lockbox "as a precaution to you, the seller" and then wait for the other agent to contact them?

I definitely don't think you have to shy away from these homes, but you need to take more precaution than you would if you purchased say a house that is only 0-15 years old. 

Familiarize yourself with local lead paint laws and be aware of the extra precautions you must take when disturbing it.Same with asbestos - it's amazing how widely used that stuff was.

What are some precautions on making a basement a “livable area”?

So taking precautions also proves your intent to minimize the risk, on the flip side sometimes you can spend all your hard earned profit in atty fees, insurance, entity structures and so on unfortunately you have to do what's best for your particular situation.

The deeper you dig, the more dangerous, the more safety precautions are needed for the install, the more money. 

If it's a really big deposit, make sure it's a reputable firm, I'm a little more wary of a solo practitioner, and sometimes ask for proof of E&O insurance just as an extra precaution.

If fireworks are used on the street, Tenant agrees to take proper precautions to prevent injury to people and damage to property, to have a means to extinguish the fireworks safely, and to clean up all firework debris promptly.