M - P numbers Spell out numbers from zero to ten unless they occur within a technical specification. Use digits for numbers higher than ten. It's what we've always done. Put a period inside quotation marks, unless the clarity of an instruction would be compromised by not doing so. Don't call it a PowerPC, though you can refer to the chip inside as a PowerPC chip.
Most writing is more forceful and convincing without it.
If you want to use a superlative, use a different term. Use he and she randomly. They plan to ship the MaxMac in April. It plans to ship the MaxMac in April. Most writing is more forceful and convincing without it.