But a client of mine sold his house and the buyer wants him to do a 1031 tax exchange amendment to the contract of late.  

Plus from the sounds of it your brother was a silent partner in the financing and is probably also on the expense side which would require amended returns and a whole level of transparency that could cause you difficulty.The easiest answer is for you to complete one (not two) 1031 exchanges and have you buy both of those properties in your name.  

That means there has to be some quick inspection and offer amendments if issues are discovered in order to stay within the inspection period. 

If you plan to bill back you'll need to amend their lease accordingly and treat it like rent, e.g. it needs to be paid at a certain point and the consequences for not doing it.Water costs me $2k a year at my duplex...I'd love to pass it along to my tenants and may start to do so in lieu of rent increases.

You're right as little as is better, I'll amend.

If you took depreciation expense on your returns other than what was allowed, you should amend your return or simply file a 3115, change in accounting method, to establish your depreciation method as your own and adjust your basis by the amount of depreciation that which you actually took.

Talk to a tax professional...you can amend your filings back 3 years.

If so, I will be amending my lease to add it.

As an investor there since 1955, and a real estate broker since 1965 and paying finders fees that passed the occasional department of real estate audits during those years, you will need to amend your opinions regarding California and a few other states.

In August 1999, TREC amended Section 535.20 of the TREC rules to provide that for purposes of that section, the term "valuable consideration" includes, but is not limited to: 1) money; 2) gifts of merchandise having a retail value greater than $50; 3) rent bonuses; and 4) discounts.