Yes and no.
The no part first: Mars 2020 had sensors and effectors attached to the non-important parts of your diagram, many of which had various degrees of smarts.
Star trackers are very sophisticated cameras. The have their own computers that control mode (e.g., lost in space versus locked) and that perform pattern matching on an self-contained star map. ...
There was a fluid loop that transferred heat from the RTG to cruise stage components, as shown in these diagrams.
Source: Thermal Control of MSL Rover 'Curiousity" Using an Active Fluid Loop
The separation of the thermal control system is described in this paper thusly:
The first major thermal event triggered by the EDL sequence was venting of the ...
See lower centre of pic, cylindrical thing is umbilical cutter, next to that is grey blocky thing being the point of attachment of support cable with cutter in block, next to that is a bunch of severed cables and pipes/tubes:
original, click for larger
Short answer: yes.
Long answer is here (Thermal Response of the Mars Science Laboratory Spacecraft during Entry, Descent and Landing - Keith S. Novak):
Flyaway Segment: at E+431 sec (see Figure 6)
After the Bridle was
cut, control of the DS was transferred to the DMCA. The DS traveled
straight up above the Rover, before turning 45 degrees and thrusting
This article says 1,930°C (2,200K) for Curiosity, which seem in line with peak Orion and Apollo values from this answer, 2,200°C (2,470K) and 5,000°F (3,000K).
As such, the surface material does not reach solar temperatures.
However, the gas and plasma immediately next to it can easily reach 10x solar temperature, and what is "surface" of the Sun ...
From the DESCANSO MSL Article, cruise communications were done with a medium-gain antenna (MGA) and a low-gain antenna (PLGA).
The spacecraft was spin stabilized:
the interplanetary trajectory attitude control plan for MSL has the cruise stage spinning at 2 revolutions per minute (rpm) until shortly before entry into the Martian atmosphere. The cruise ...
After dozens of test, I found the way.
Payload to be sent over POST query: