i was going to go the synthweaving , archaeology, and under world trading route. But a friend of mine told me that those skills are not very helpful if i want 55 tank gear. any suggestions.

Your friend is somewhat correct: the gear crafted by synthweaving is not very good at the level cap. BUT it does produce augments that do help Jedi guardians (redoubt = defense rating) and augmentation slot kits to add augment slots to gear.

For a detailed look at what the "best" crew skills are, see my guide: http://www.swtor.com/community/showthread.php?t=726927

Taking companion bonuses into account, Jedi kinights are generally considered the best biochem in the game; taking biochem, Bioanalysis, and diplomacy. Afaik, only the imperial agents' companion (forget which one) has a better crit (+5) for diplomacy.

I have a sentinel biochem. Doc crits like crazy on adrenals and stims for my alts & main. Luv it.

Well, if you're looking for Level 55 gear, your best bet is to do Operations, and as a level 55 Guardian Tank, if you're decent, you'd be in high demand.

Self-gearing through crafting is only really viable (IMO) up to level 54. Cybertech would get you Armorings and Mods, Artifice would get you Hilts, Enhancements, and Color Crystals. Synthweaving would get you Augments and the Kits at 55, but that's a tiny input into the overall scheme of things and purely optional unless you're planning on running HM or NiM 55 Operations.

Given that, I'd second the recommendation to go Biochem. In addition to Doc having the best Biochem crit rating in the game (+5), at Biochem 450, you can use the reusable stims, adrenals, and medpacks, meaning you're going to save a bunch of money you won't have to spend on the consumable versions.

My main is a Guardian Tank and I occasionally have moments of regret that she has Synthweaving instead of Biochem. But, back when I rolled her, I had no idea I was ever going to play endgame, so, ah well.

Taking companion bonuses into account, Jedi kinights are generally considered the best biochem in the game; taking biochem, Bioanalysis, and diplomacy. Afaik, only the imperial agents' companion (forget which one) has a better crit (+5) for diplomacy.

 

I have a sentinel biochem. Doc crits like crazy on adrenals and stims for my alts & main. Luv it.

Well. JK has no crit on diplomacy. Trooper and Consular have +2 crit (Aric, Nadia), and agent has the +5 you mention (Vector). I am all about taking advantage of crits, to a borderline OCD level But diplomacy is hands down the one skill where it matters the least, IMO. Purple items one crafts not so many, so purple mats matter way less than in any other skill. What mattered more to me is the LS/DS thing with diplomacy. My JK is probably the most light side char of all. Having only darkside missions in the list way too often annoyed me so very much. Naturally one can do the usual to change the lists of missions, but meh. Diplomacy is really best situated in a neutral char, IMO.

My main is a Guardian Tank and I occasionally have moments of regret that she has Synthweaving instead of Biochem. But, back when I rolled her, I had no idea I was ever going to play endgame, so, ah well.

How about switching? It is not just the reuseables, but also the drops that would be fun to me (RE'ing implants). Naturally, if you have schematics in synthweaving that are super rare, that would hurt...

How about switching? It is not just the reuseables, but also the drops that would be fun to me (RE'ing implants). Naturally, if you have schematics in synthweaving that are super rare, that would hurt...

I consider it occasionally...for about two seconds.

I don't know if the schematics my Guardian knows are 'super rare', but I've sunk I don't know how many credits into buying up as many schematics I could lay hands on, not to mention unlocking several artifact level Augments. The thought of losing those pains me more than the ongoing low-level annoyance of having to keep her supplied with consumables by my Biochem toon.