Castor Oil is the best fixed oil to use with Essential Oils, and causes the fewest problems with solubility. However there are far better solvents you can use, if you don't stick to the unnecessary bind of "all Naturals".
Your fragrance seems to be mainly top note, with a little back. By "Tobacco", do you mean Tobacco Absolute? If you do it is a middle to base note. By "Vanilla", do you mean Vanilla Absolute? If you do, it is considered a back note. The rest of the oils you use are mainly top, although Essential Oils are difficult to classify as the various chemicals within them evaporate at different rates. However Orange and Lime, are mainly d-Limonene, whilst Juniper is mainly Pinene. Limonene and Pinene are top notes, with high volatility.