Well, let's narrow this down since you seem to have this large scope of trying to do too many things at once. This is something common to a lot of people in this game - losing focus and trying to accomplish too much.
Let's look at the following you mentioned:
What purpose does ameterasu serve your team? While Ameterasu is OK for certain encounters...she loses functionality as you progress. That 4000 heal a turn turns from a full heal into well.. putting a bandaid on a gushing wound. She's absolutely not necessary, and you're typically better served with a max skill siren as a sub member than ameterasu as a main member. Note - months ago when everyone was kind of weak and didn't have such good helpers, ameterasu was a fantastic way to clear out a lot of content. She's lost a lot of her luster as the game opened up and progressed.
Let's look at common valkyrie team compositions - Note, having a valkyrie segways very well into a zeus team, but first we must identify...what is your goal in this game? Ideally, you must focus on a team and / or certain monsters to clear out various dungeons. Preparing for the event you're looking forward to must be your #1 priority. Will the sky dragon el dorado help you at all? Probably not - so while you can probably clear him if you level up a red ripper, in the grand scheme of things, it's most likely a lost cause (and eventually you could just kill him with a zeus or lakshmi team)
Valkyrie team compositions typically involve a max skill siren (note - max skill siren is fantastic on multiple teams. If yours isn't max skill, i'd highly suggest this) Echidna's are fantastic here as well. Lilith is a niche monster only great versus certain bosses. Another two honorable mentions on the team are rainbow keeper (high hp, defensive cooldown but doesn't benefit from the damage bonus) or verche - dark -> light conversion, which allows you to cover all of the colors on your team. Team with a valkyrie for damage dealing, and resolve if the dungeon calls for it. Valkyrie is great against all normal dungeons, tech dungeons, and hera. It's not useful versus Zeus or two heroes.
Parvati team will take more work to get useful. ADKs are useful team members, red -> green. Cu Challain is fantastic, farmable (from two heroes) and provides hearts -> wood orbs. Other useful monsters are susano, a green golem if leveled up(note you can skill these up with keepers). Mechs are good for high HP and attack. Rippers aren't really useful at all, but you can use it temporarily on the team. An honorable mention is always an echidna on the team, for delay on attacks (this always helps)
You can most likely use your parvati team versus two heroes to farm cu challain if you get it leveled enough. You most likely cannot Zeus. Dark teams (notably you can farm a vampire, farm 2 heras, use an echidna and perhaps a CDK with a loki of zeus friend) and minimize your stone usage on clearing out zeus.
Leveling rippers will allow you to farm more content, but is this content absolutely necessary for you to have now, or can it wait til later?
Lets look at various hera compositions if you go after her. A common, extremely safe one is:
CDD leader, rainbow keeper, 2 max skill sirens, lilith, and odin friend. This is extremely safe but takes forever. Easily can get through with 0 stones
Valkyrie team w/ orochi helper can clear this dungeon quickly but also requires manual healing. However, missing a heal in this case is fatal.
Id highly suggest just picking something like:
I want a blue team! or I want to work on my green team! or valk team, or whatever. I'd like to suggest that your parvati team will probably carry you the furthest unless you want to segway the valkyrie team into a zeus team. Meh, typing books. You just need to pick something and once you decide what you want to focus on, it's a lot easier to think of what you need to proceed with it.
