Plenty of evidence... the question is only if you feel the inner-dependency was acceptable or shady.
The relationship and authority put into RCES vs the board is.. generous. The contracting of Disney services instead of open market. The extended perks Disney extended to RCID staff (like retirement perks, etc). This was a cozy, self-serving relationship... but one that was above the line.
There is plenty of intermingling... there isn't anything to necessarily suggest RCID acted NEFARIOUSLY, but they certainly were not fully independent. Their motivations were aligned with Disney... and even the infamous '11th hour' agreements were all completely one-sided and generated by Disney.
I get that the RCID - Disney relationship can seem inappropriate on first impression, but I really don't see anything that's even arguably shady here.
Re. RCES, the new board paid outside consultants a lot of money to find fault there, and they were visibly disappointed when none was found. I admit I'm confused about your reference to "the relationship and authority put into RCES vs the board", but it's a big and complicated situation and I only know a tiny piece of it so I'm open to hearing more.
The 'perks' (by which I assume you mean the AP's) have been discussed in this thread at length. The district bought them from Disney, just as other 3rd party businesses in the district did. There was nothing inappropriate. Yes, the district's taxpayers bore that cost, but who are the taxpayers? On the other hand, the district's proposed replacement plan could cost the taxpayers more while still ticking off many employees.
The "11th hour" agreements essentially enforce the Comprehensive Plan which RCID completed (as required by statute) in mid-2022 and which was approved by the State of Florida. How are they "one-sided"? As far as I can tell (based on my extremely low level of knowledge about these things) the agreements are not unusual - if I'm wrong about that someone please let me know.
The district (both RCID then and CFTOD now) is
supposed to be inter-dependent with Disney, because its
purpose is to support the development of WDW. Its obligations are to the landowners, who in this case are mostly Disney plus a few others who depend on Disney's success. For that matter, any government's actions and goals should be inter-dependent with those of its constituents. Concerns about self-dealing, cronyism, etc. are generally related to government officials making decisions that benefit themselves, family, friends, big-interest donors, etc. at the expense of the taxpayers. At first glance, yes, Disney is a "big corporate interest", but in this particular situation they are also
the taxpayer. The district landowners have already paid all their taxes to the other levels of government, including Orange & Osceola counties. The taxes collected by RCID/CFTOD are an additional levy that is intended to support development of the WDW resort area. A decision that benefits the WDW resort benefits the taxpayers.