Calculating current in an unknown transformer with multiple isolated secondaries
The current flowing in primary at 230V was 0.07A. Using the turns ratio I we can calculate the current flow in each secondary:
S1: 0.07 * 1.549 = 45 mA
S2: 0.07 * 0.150 = 460 mA
S3: 0.07 * 0.028 = 2.495 A

I didn't read through the whole post but I suspect that your secondaries were unloaded (open-circuit) and the actual secondary currents therefore were zero.
Unfortunately this renders the rest of your post irrelevant!#

Figure 1. A 50 / 60 Hz RS 100 VA transformer. Dimensions: 89 x 68 x 75 mm. Weight: 1.6 kg. Source: RS-online.
You don't give any indication of the dimensions of your transformer. With 230 V x 0.07 A you have a load of 16 VA which might be reasonable for a &gt; 100 VA transformer. (A 100 VA transformer would weigh about 1.6 kg.)
Your primary current is just magnetising losses on the primary.