Is DDR5-6000 guaranteed on every AM5 build?

No. G.SKILL states that XMP/EXPO rated speed requires overclocking/BIOS adjustments and depends on the CPU and motherboard.

Can I add this kit beside another kit later?

Avoid mixing kits. G.SKILL says matched kits are designed to run together and mixing can cause instability.

No. The exact G.SKILL specification lists non-ECC, unbuffered DDR5 UDIMM.

Will it clear large coolers?

The module height is 33mm, but cooler clearance must still be checked against the exact board and cooler.

G.SKILL Flare X5 32GB DDR5-6000 CL30 EXPO/XMP Kit

Name: G.SKILL Flare X5 32GB DDR5-6000 CL30 EXPO/XMP Kit
Brand: G.SKILL
SKU: F5-6000J3036F16GX2-FX5
Price: 704.87 EUR
Availability: InStock