How does Shadow Sneek Attack Progress? Will it work with Strategic Strike?

Two question here. I am currently playing an Investigator in a Pathfinder 2e game. Thinking about going Shadowdancer.

A. How does Shadow Sneak Attack Progress? Is it just 1d6 forever, or does it progress on 11th and 15th levels?

B. Can it stack with Strategic Strike as Strategic Strike is not Sneak Attack?

Roll For Shoes – Does the advancement system work for longer campaigns?

I’m about to start in on a new campaign with the Roll For Shoes system, but I’m concerned that the characters will swiftly outstrip basic and intermediate challenges as they grow in dice.

In the title I mentioned "longer" campaigns. I’m defining "longer" as at least 72 hours of game time spread out over maybe 18 sessions, with hopes of room to grow.

Here is an example:

Ryan has Do Anything 1, and begins a life of roguishness. He starts breaking into houses and achieves Skulduggery 2, starts using lockpicks for Tools of the Trade 3, then eventually gets to Lockpicking 4 and maybe Safecracking 5.

Meanwhile, the GM needs to provide appropriate challenges for Ryan. When Ryan starts out, he somehow has to break into a house with one die. If he can manage that, the GM will later need to provide an appropriate challenge for Ryan’s 4-die Lockpicking skill.

From a story perspective the GM can always provide stronger locks and reasons, but by my very rough estimations getting a character to a four die skill could easily happen in a 4-hour session if the game is moving smoothly.

Does the RFS advancement system work for longer campaigns?

Will the feat Spell Sniper work with the Spell Shadow Blade?

Will the feat Spell Sniper work with the Spell Shadow Blade?

Spell Sniper

Prerequisite: The ability to cast at least one spell

You have learned techniques to enhance your attacks with certain kinds of spells, gaining the following benefits:

  • When you cast a spell that requires you to make an attack roll, the spell’s range is doubled.
  • Your ranged spell attacks ignore half cover and three-quarters cover.
  • You learn one cantrip that requires an attack roll. Choose the cantrip from the bard, cleric, druid, sorcerer, warlock, or wizard spell list. Your spellcasting ability for this cantrip depends on the spell list you chose from: Charisma for bard, sorcerer, and warlock; Wisdom for cleric or druid; or Intelligence for wizard.

Does Spare the Dying work on a creature with less than 0HP?

Spare the Dying states:

You touch a living creature that has 0 hit points. The creature becomes stable. This spell has no effect on undead or constructs.

Given the Strict interpretation of RAW it would seem that you would have to have exactly 0hp to benefit from Spare the Dying. Is this correct, or does it stabalize creatures with less than 0hp as well?

How does absorb elements work with pre-existing resistances

So I’ve looked around and can’t find an answer that quite fits what I’m wondering. For example if I were to already have fire resistance and I get hit with a red dragins fire breath would casting absorb elements halve the damage I take(effectively making it 1/4 damage) or not reduce damage at all because I already have 1 source of resistance