Very nice!
All the SH models from SHIII to SH5 use the same scale. I am sorry that you had to waste your time on checking that, before I could solve your doubts.
In the EcoMod as well as in TWoS there are rulers for measuring objects in game (from the style of the TWoS ruler, I think it is my work, but as I had completely forgotten about it, I created a similar one for the EcoMod). Nonetheless, the quickest way to measure game's 3D objects, is by exporting their meshes and measuring them in a 3D modelling software. One unit measured in any of the commonly used 3D program is equal to ten in-game meters.
If you specify what kind of lightmap you want to add to the model, maybe I can help you with it.
Finally, IIRC TDW's particle effects are done in a way that they can only be edited using an hex editor. You can use his flare effect as it is, but its particle generator(s) might be pointing to textures and materials contained in FXUpdates, so you need to have that mod (or TWoS) installed for the effect to work...