[Luzzifus]

#1 - try this:

local raid = {}
for i = 1, 5 do
	local raidgroup = oUF:Spawn('header', 'oUF_Raid'..i)
	raidgroup:SetManyAttributes('groupFilter', tostring(i), 'showRaid', true, 'xOffSet', 12, 'point', "LEFT")
	table.insert(raid, raidgroup)
	if(i==1) then
		raidgroup:SetPoint('TOPLEFT', UIParent, 'CENTER', -135, -225)
	else
		raidgroup:SetPoint('TOPLEFT', raid[i-1], 'BOTTOMLEFT', 0, -12)
	end
end

#3 - Try the detailed notation:

self.Health.value:SetPoint("BOTTOM", self.Health, "BOTTOM", 0, 2)

And also make sure to call "self.Health.value:ClearAllPoints()" before, if it is not the first time you set the points.

#5 - Use this one instead:

local number = function(n)
	if n >= 1e7 then
		return ('%.1fm'):format(n / 1e6):gsub('%.?0([km])$', '%1')
	elseif n >= 1e6 then
		return ('%.2fm'):format(n / 1e6):gsub('%.?0+([km])$', '%1')
	elseif n >= 1e5 then
		return ('%.0fk'):format(n / 1e3)
	elseif (n >= 1e3) or (n <= -1e3) then
		return ('%.1fk'):format(n / 1e3):gsub('%.?0([km])$', '%1')
	else
		return n
	end
end