TheRK9

Have you joined one of the gangs? If not, you can choose to join either the Aqua or Magma gangs in the Lapis and North Obsidia Wards respectively. After doing so, there are 2 side quests that need to be done, and after completing those you speak to your gang's leader, who will give you access to an area called 7th street. After you reach 7th street, just walk around and talk to people, some will sell you stuff or teach you moves, or initiate sidequests, so it's good to talk to everyone here regardless. You will be given some hints which will allow you to find [SPOILERS], who will open a path to [SPOILERS] where you can [SPOILERS] [SPOILERS].

You can find Beedrill in the Jasper Ward and Malchous Forest Park.

I heard you solved it, but for the record the Toxic TM is pretty easy to get through the Tara's Identity sidequest. You can also pick up an Amoonguss from one of the mushrooms in Azurine Island, it's a good defensive Pokémon overall, gets great utility with Spore, Regenerator, Clear Smog and Synthesis by level up, and, of course, Toxic.

You have to go through a New World to get there. The Chrysolia Deepwoods is part of the normal world, but you can't get there without the New World portals. The portal you need to find is in the southernmost part of the Chrysolia Forest, the route there is kind of hidden but just look around for a bit. It's where you find the abandonned train with the Maractus/Cacnea egg.

The X-Scissor TM was changed for a Slowbronite in E19

As far as I know, you can't get Emolga while it's raining. You can change the weather by changing your date, however doing so will lock the weather until you catch up to that date if you turn the time back, which might be why you can't change it. You can get another datachip in the orphanage, but until then you're out of luck if changing your date didn't work. You could always just enable Debug to get another Datachip though.

Get the Sunny Day TM and any move that can set the field on fire and you'll be fine.

I see you found it, but I will point out that it needs to be night time and windy for the Murkrow to appear, and you need to have joined Aqua Gang. Keep that in mind once you beat up Kiki.

I was thinking of Toxapex but people usually yell at me whenever I mention that Pokémon in any context so I decided not to. It's a fantastic option though.

No problem!

You need a spare mon to trade, I'll wait

I can trade you one, my online ID is TheRK9, send me a request whenever

You can get the pinch berries from the Malchous Forest after City Restoration. Reborn is based on gen 7, so they heal 50%.

I'll make suggestions based on a general teambuilding perspective rather than specifically counterteaming the E4, partially because it's more fun and to avoid spoilers: I would recommend Serperior or Lycanroc for Terrain control. - Grassy Terrain synergises best with your team by boosting Blaziken, since the other ones don't really benefit you. It also gives you another Ground type resistance, and covers your team's inability to deal with Water types. Contrary Leaf Storm is obviously amazing, and Nature Power is extremely good in this game as well. Grassy Terrain is an egg move though, so it is a bit annoying to get. If you want I can trade you a decent Snivy. - Lycanroc is amazing because Splintered Stormshards removes the field permanently, whereas any manual terrain is temporary. It also gives you a much stronger initial damage, and offers you a proper counter to Flying and Fire types. Strong Priority is also something you literally cannot have too much of. As for weather control, you honestly don't really need it. Your team isn't built to benefit from any given weather, and only one of the elite four actually utilises it. I would recommend that you just teach one of your Pokémon the Sunny Day TM for that specific fight and then forget it. For a final team member you can get almost anything. I would recommend a Grass type if you didn't get Serperior because you are very weak to Ground and Water types otherwise. If you got Serperior, I would recommend a Rock or Electric type for Flying types, or a Sticky Web setter for speed control (Galvantula can notably do both)