[RPG] Fighting against a Spirit – Only 1 Mage

The wording of the section on Mana Barriers is talking about magical force to break through the barrier, not physical force. The comparison it makes to any other physical barrier is to inform you to use the same system for tracking damage to the barrier.

On page 315 in the entry you mention there is a chart which describes the caster's options for where the barrier will be present, and lists the specific page governing the spell or effect which causes the barrier. Mana Barrier itself can be found on page 294 of the 5th Edition core rules, and describes a barrier which does not prevent the passage of non-living (physical objects) or living things unless they are 'magically active.' For comparison, the next listed spell is Physical Barrier.

Unbound/uncontrolled spirits active in the area are affected by the barrier and have to contend with it like anyone else. Whether or not a summoning could take place on the other side of the barrier would very much depend on the situation and the barrier.

If a mage (or other affected being) desires to pass or have an item which is affected pass through the mana barrier they have three choices:

1. The subtle way is trying to magically bypass it as described on page 316, where every additional hit allows them to slip other affected items or beings through with them. This is described as pressing through the barrier, much like Dune's 'the slow knife will penetrate the shield.' This approach does not automatically notify the creator of the barrier

2. The forceful way is to target the barrier with damage-causing magics. This is handled 'just as you would with any other barrier,' by dealing with its Armor and Structure ratings. These ratings are equal to the Force of the mana barrier. The barrier must be overcome in one Combat Turn or else its Structure refreshes. This approach automatically notifies the creator of the barrier.

3. The third option (page 317, sidebar) is to attack the source or basis of the barrier. In other words you can deal with the anchor, destroy the lodge, or geek the mage responsible for sustaining the barrier. With the source out of the way, the barrier is no longer a problem. This approach, if it brings down the barrier, will notify the creator automatically.

These choices are the same regardless of where the barrier is on the Astral Plane, on the Physical Plane, or on both.

Mundane gear and allies are unaffected by Mana Barriers.

Affected beings or items cannot normally pass through the barrier, unless they Press past it or bring it down. In some cases a mundane object may force them through the barrier (page 316) in which case they must pass an Opposed Test or be disrupted.

The effects of disruption are listed in the Astral Intersections passage on page 316. Foci are deactivated, spells end, spirits are dispelled, and living beings are Stunned. Afterward, foci can be reactivated, spells can be cast again, spirits can be summoned again, and living beings will recover from Stun... providing the owner of the mana barrier gives them the time to do all of this.

No amount of time is listed as a penalty for passing through a mana barrier, just the condition resulting from that intersection. Using the details of that imposed condition indicates a deactivated focus can be reactivated by the person it is bonded to as a Simple Action - if they are conscious. Likewise, spells and spirits can become available again in the time it takes to call them forth. Living Beings will recover from Stun normally.

1) Correct, as long as a Natural Weapon is used for the attack. Without a natural weapon things would have been different. Also no Astral Combat skill is needed, if a natural weapon is used.

p. 399, Natural Weapon critter power

A dual-natured critter with a melee Natural Weapon can use this power against astral targets that are within its reach. Use the critter’s normal Unarmed Combat skill and physical Damage Value for this attack.

2) You're wrong. Dodging is done using Logic+Intuition; "soaking" means reducing the damage after a successful hit. Since the mage is only astrally present, Willpower (see table p. 314) is used to soak damage. (Manifesting doesn't make the mage vulnerable to attacks that wouldn't hurt her, if she would project without manifesting, so it's still astral combat)

p. 315 Astral Combat

Astral combat is resolved in the same way as physical combat.

p.314 Manifesting

Manifesting is a psychic effect that lets you make yourself visible and audible on the physical plane through an act of will. [...]

You can’t interact with anything physically (or be harmed by physical attacks). [...]

You’re still on the astral plane, so astral attacks can still target you.

4) Even if the mage would not be dead immediately, filling all boxes would basically kill her, since finding the body (p. 314, While you were out) would be impossible, if she is knocked out.

What could the mage have done?

1. This is Shadowrun. You don't just walk up to a potentially dangerous stranger and say "Hi"; you gather all info you can get, then maybe you talk. A better approach would be to stay in the astral and check that being using Assensing(assuming the skill rating is high enough to make it work with that INT attribute). Most paracritters shouldn't be too good at masking, so the mage would likely get the info that she is dealing with a dual natured being and would have approached it with more care. With the high move rate in the astral evading it shouldn't be too difficult unless the mage is in meele range and surprised.
2. What about burning edge? Not Dead Yet (p. 57) could have saved her.