Fulfilling such a diverse set of requirements would necessitate a compromise approach which would
likely result in a versatile ‘jack-of-all-trades, master-of-none’ spaceframe * 4 .
* 4 This may have the added advantage of confusing Shivan adaptation algorithms due to presenting
no clear weakness to adapt to, although some analysts disagree and dismiss this as wishful thinking.
I'm not an expert on BP lore, but with the idea behind the Shivan tech being "incredibly advanced but not directed" the concept of building more generic ships seems a horrible idea to me.
Probably the easiest way to built a GTVA-UEF hybrid would be to slap missile batteries on a Raynor or a Titan.
If you want overpowered point defense, use Maxims as turret weapons - on top of the range, fire rate and the ability to destroy hostile beam turrets its munition is most likely much less cargo intense than any flak weapon, ROF makes up for the lack of an area effect.