Seems to me that there is always a problem trying to have everything in one list (atleast for me)
Eldars are still the best non-daemon codex for summoning daemons, so you should stick to that fact and focus to overcome durability and firepower issue.
I would consider streamlining the Eldar part and changing the nature of the
AM part to contain more supporting fire of you want to keep them in the list as they have plenty of options for cheap firepower. Also in this list the vets may not be the best option for troops.
In overall you want to have as much bodies as you can get to hide your psykers from incoming fire since you can't buff properly. Jetbikes are the way to go since they have Jink and T4 so S6/7 weapons won't instagib your farseers anymore. For this use the new Jink rule got better as you can have the save even if you go second as they don't have to move in order to get it. To get the most out of it you have to get your warseers and warlocks on jetbikes too but that costs some points. This way you get movement bonus which helps you to dash from
los block to another and helps you to get daemons where you need them in maelstrom missions. Majority toughness gives them the toughness boost anyway until they have lost enough jetbikes.
You could also consider having one farseer and few warlocks on jetbike and join them to jetbike unit and another farseer and warlocks on foot with guardians if the points become an issue.
In a pure Eldar list I would add Wave Serpent to those guardians to get some dakka, but if you want to keep Astra Militarum as allies I would take heavier weapons from them and preferably Forgeworld units if that is allowed where you play.
For the
AM allies I might try switching one primaris psyker to ministorum priest and switching vets to a single vet team and platoon with as many bodies you can get with the points left. Having a 15+ blob with primaris psyker and ministorum priest will be much durable than vet team with primaris psyker. Ministorum priest gives them a decent change in melee too.
I would skip the Valkyrie and Executioner too as they are point sinks when taken alone.
Something like this as a base and then customized to different situations.
Farseer: runes of witnessing; Eldar jetbike
Farseer: runes of witnessing; Eldar jetbike
10 Windrider Guardians
10 Windrider Guardians
6 Warlocks: 6× Eldar jetbike
Ministorum Priest
Primaris Psyker: Mastery Level 2
Veteran Squad: + 1 Veteran Sergeant
Platoon Command Squad
•
Infantry Squad: + 1 Sergeant
•
Infantry Squad: + 1 Sergeant
•
Heavy Weapon Squad
1 Basilisk