We're a team of 4 (two of us are founders) and the other two are early employees.
When we go pitch VCs to try and raise a seed round, should the entire team go or just my co-founder and I?
One issue is that both of us are non-technical founders. So if a VC asks any questions regarding tech, we would need our engineers.
In general, you want to limit the number of people in meetings with VCs to an extent. If one of the employed engineers are senior level and the other is not quite as experienced, I would suggest bringing them along. Even saying that, it may be good to have the whole team since you've got just four people.
A few things to consider aside from the experience of the engineer(s).
Alternatively, if the VC does have a technical point of contact, invite them for a pre-meeting with just you and the engineers ahead of time. This conflicts slightly with my point #4, but does often yield good results and shows strong cooperation.
If they do not have a technical contact, consider suggesting that you contract a reputable 3rd party engineer and have both meetings with them. Specifically find one that has similar business experience under their belt. The investor(s) may wish to select their own, but suggesting it shows that you're serious about the sound technical quality of your product/service.