Is it possible to do the EASA Part 66 B1.1 exam modules first and do the practical training afterwards? Also, is it possible do the exams and training in different European countries?
I know very little about EASA regulations, but it looks like your first question is answered in EASA's Part-66 FAQ:
I have completed my EASA Part-66 modules for B1 and I have passed all the exams, but I still lack experience to get my licence. Is there a time limit to get the licence ? Will the certificate expire in a few years if I do not get the experience?
According to Commission Regulation (EU) No 1149/2011 of 21 October 2011 (amending Regulation (EC) No 2042/2003), the basic examinations shall be passed and experience shall be acquired within the ten years preceding the application for an aircraft basic licence. The new regulation also states that for the purpose of time limits related to basic knowledge examinations, basic experience acquired before the Regulation applies, the origin of time shall be the date by which this Regulation applies, which is 01/08/2012 (which means until 31/07/2022).
I couldn't find any clear answer for your second question, but another FAQ item might be relevant:
Where do I gain the required basic maintenance experience? Is it mandatory to gain the required maintenance experience in an EASA approved Part-145 organisation?
According to the AMC 66.A.30(a)(4), aircraft maintenance experience gained within different types of maintenance organisations (under Part-145, M.A. Subpart F, FAR-145, etc.) or under the supervision of independent certifying staff may be accepted by the competent authorities. This means that the aircraft maintenance experience may be accepted by the competent authority when such maintenance is performed in a maintenance organisation which does not necessarily hold an EASA Part-145 approval. However, it is on the competent authority to evaluate whether this experience is acceptable.
Consequently, please contact the competent authority where you intend to apply for a licence, in order to check whether the basic experience would be acceptable, with detailed information on the type of aircraft, its operation and the nature of the work.
In other words, ask the authority in your country.