There wasn't many things to be aware of when I was compiling neutral and blockstrings related tips, so instead I summarized how I normally approach those situations. These are personal opinions of a Melty ojisan, so there may be some points that are wrong. If there are any incorrect pieces of information or places that could be improved please feel free to point them out. Thank you for your consideration.
4BC is incredibly strong and is an easy way to limit other characters movement. Also while it's a universal system Moon Drive is a superior tool. Utilize 4BC until the gauge drops to about half then start to be conscious of Moon Drive, this way you can make the best of both options. Moon gauge is easy to fill up mid-match and Roa has plenty of superior moves so let's actively use it.
236C and 214C are strong tools so we'll be focusing our meter around these 2 moves. Since these 2 moves are superior I normally won't use Arc Drive or Last Arc. When on defense I try to save at least one bar to prepare for using Forced Release, but aside that let's actively use our meter.
Roa is a character who mainly approaches neutral at the mid-range.
214A, 214B, and 214C are stable tools to poke at people trying to forward dash
While just slightly inferior to the above mentioned, you can space control with 214[B] or 4BC
If the opponent tries to guard against 4BC by using super jump, go for air throw while they block
While assessing the situation try poking with rising jump attacks, 623X, or 2A, 2B, or 2C against their landing
Once the opponent has stopped moving go for instant air-dash mixup
(Against specific characters) Use 236C against projectile characters
These are the 5 (+1) fundamental things I think about while fighting. When you have more than 2 meter or are at the health deficit and put into a situation where you need to attack let's proactively try to aim for the first option. If you get the opponent to block in the air try to go for air-unblockable attacks (for example 2C) since you can combo from it, or if they continue to block you can forward super jump or instant air-dash to open them up.
In the case 4BC hits you can use the following of the two options. If spacing and height judgement seems hard let's just turn everything into 236C.
When midscreen go for okizeme after 236C
In the corner use 236A or 214C into a combo
Roa's only tool that allows him to continue pressure while going for high/low options is after 214C. Because of this once you have the opponent blocking let's decide to an extent which direction we want to take our blockstring.
Commonly Used Stings
2A > slight delay B or C to frame trap
Buttons > 5C > 5A > delay A followup (Rapid Beat) to frame trap
2CC > 5A or 2A > restart the blockstring or instant air-dash
Buttons > 6C > j236A > backwards jump
If you noticed from these strings, basically all of them can be low shielded so against opponents who frequently uses shield it can be bothersome. Once you know the opponent likes to use shield, don't try to extend your pressure and instead let's try to quickly convert into instant air-dash mixup.
Instant air dash is his fundamental mixup option so I'll be omitting this part. I'll often use forward dash into backwards airdash jC, but that's mainly for throw baits. Leaving out the specifics this is gist of his mixups. There's a lot of points I haven't mentioned so if you have any questions please feel free to ask.