Will Photon Geyser become a physical move after Swords Dance?
Yes, as long attack is higher than special attack afte Swords Dance.
Will Photon Geysers Power gets reduced when Burned and when Atk is
Yes, Photon Geysers becomes a physical move, the power will be halved when burn.
Even after Swords Dance will Photon Geysers damage be based on SpD
No. As answered before Photon Geyser becomes a Physical move and uses the opponents Physical Defense stat.
"+4 252 Atk Necrozma-Ultra Photon Geyser vs. 0 HP / 4 SpD Kyogre: 441-519 (129.3 - 152.1%) -- guaranteed OHKO
The Def stat had no EVs and Photon Geyser after becoming Physical gaurantees OHKO."
"+2 252 Atk Neuroforce Necrozma-Ultra Photon Geyser vs. 0 HP / 4 SpD Marshadow: 1072-1262 (333.9 - 393.1%) -- guaranteed OHKO"
hope I helped