What's the syntax of sine voltage to provide few DC volts, amplitude, phase, offset on xschem? Is there any difference in syntax when entering values in code.sym or directly in vsource.sym? Also, does the syntax vary for transient, DC and AC analysis?

1. Its documented in ngspice's docs. 2. Yes there is. Code is directly lasted into final spice. In vsource only the voltage source type is specified (pwl, dc, pulse, sin) without pins and stuff. 3. I think the syntax is the same but they behave differently in each analysis mode.