Yes, it can. The IGS-10080MFT supports AC 24V power.
Yes, they can. However, please be noted that the IGS-10080MFT supports DC power from 12V to 48V and supports AC power of 24V only.
Yes, it does, Because they equip the same 15km single-mode fiber optical interface. But, please have noticed that the ISW-511S15 operating temperature is from -10 to 60 Degree C only.
Do I have any way to recover it? Is it possible to reset to factory default?
I had also tried to operate it by using Console but just showed like below:
Image Loader 1.0.0.1
Loading Diagnostic Image File : Diag_1010.bix
--- Performing Power-On Self Tests (POST) ---
DUMMY Test 1 ................. PASS
UART Loopback Test ........... PASS
DRAM Test .................... PASS
Switch Int Loopback Test ..... PASS
Done All Pass.
------------------ DONE ---------------------
Answer:
In regard of the situation as your described,
Please kindly refer to following procedure under IGSW-2840 Console interface and solves this issue.
1. Please use console cable to connect with PC and IGSW-2840 then set COM1 port parameter as 9600, 8, N, 1 then use communication tool (such as Hyper terminal) to get into console interface.
2.Please press “Esc” key when the “--------DONE----------“message appears, then please press “D” for delete file.
3. Please input “startup1.cfg” after File name to delete:, then the following message appears;
This is startup file, you sure you want to delete it (y/n)? Please input “y” for delete this file.
4. Please input “Q” to complete the factory default procedure of IGSW-2840, then the IGSW-2840 will reboot automatically.
5. After IGSW-2840 power on complete and it back to factory default mode.

The major difference is the operating temperature range.
IGT-902/902S:-10 ~ 60 Degree C
IGT-902T/902TS/905A:-30 ~ 75 Degree C
Planet has provided MFB-TFX and MFB-TF20 for industrial media converter or industrial switch, which is working on the -40 to 75 Degree C environment.
No, the IFT-802T could not connect to IFT-802TS15, because IFT-802T equipped 2km multi-mode fiber optical interface but IFT-802TS15 equipped with 15km single-mode fiber optical interface. Our suggestion is let IFT-802T connect to IFT-802T or IFT-802TS15 connects to IFT-802TS15.