Nellisir
Hero
As someone who routinely disallows PHB races (halflings, half-orcs, drow, tieflings) and creates new ones (leshii, troldfolk, talvijotun, firjotun), I like what I see. It looks like it'll be guidelines and advice rather than rules and dictates.
Also, remember that ability bonuses aren't the only way to emphasize an ability score. I stuck to the PHB model, so firjotun (hill giant-blooded) only have a +2 Str bonus, but they have other abilities that reinforce it. Not every firjotun is stronger than every dwarf, but they use their Strength more. Talvijotun (frost giant-blooded) only have a +1 to Str (+2 Chr), but have some of the same features so they "feel" stronger than they are.
Also, remember that ability bonuses aren't the only way to emphasize an ability score. I stuck to the PHB model, so firjotun (hill giant-blooded) only have a +2 Str bonus, but they have other abilities that reinforce it. Not every firjotun is stronger than every dwarf, but they use their Strength more. Talvijotun (frost giant-blooded) only have a +1 to Str (+2 Chr), but have some of the same features so they "feel" stronger than they are.