Questions for Someone New to Looking at Corporates

Hi WSO. I recently started at a new role analyzing corporate debt. Having not worked in a professional role researching companies previously, I'm looking for some clarification on some topics that are relatively new to me. I unfortunately only have very senior level coworkers above me, and while I generally think there are no stupid questions, I feel like I've exhausted my ability to get understandable and clear answers on what I've written below, and don't want to piss off my new coworkers by saying their explanations didn't make much sense to me. I understand that the below is a lot, so I'm particularly interested in questions 5, 1, and 2 (in that order) if you only have a few moments to respond. Thank you in advance!

1) When calculating adjusted EBITDA, is it standard practice to simply take the EBITDA calculation the company provides (if provided) or will you derive your own EBITDA with no consideration to what management's provided? If the latter, how do you know you've considered all possible add-backs that are appropriate?

2) When calculating adjusted EBITDA, there are some clear add-backs I'm familiar with, but there are also some add-backs I've seen that have never been in anything I've studied predominantly because accounting in the real world is always more complicated that in finance 101. For example, what is industry practice for handling amortization of deferred lease incentives? How do you go about handling accounting topics that you've never seen before so you can understand if it'll impact value / cash flow? Do you have an accountant on site to answer questions you have, do you ask your coworkers, do you read accounting text books, etc.?

3) When calculating interest on a bond issued at a discount or premium that pays a below market or above market coupon, is it industry standard to calculate cash interest based on the par value and the stated coupon rate and then add to the straight-lined amortization of the discount?

4) In line w/ 3), is amortization of deferred financing costs included within interest expense or amortization of intangibles? I know that FASB recently came out w/ new GAAP accounting guidance for which it should be included within interest, but I'm curious about what I should consider for companies that didn't adjust in 2015 FYEs.

5) When calculating FCF, I've been told to use EBITDA - CAPEX - Cash Interest - Cash Taxes - Increases in NWC - other recurring cash flows. I understand that this will get to a pseudo OCF - CFI, but there are a few points I'm not sure about. A) If you don't add back all non-cash OPEX to EBITDA and you don't subtract it out in FCF, you could end up with a warped sense of cash flow for that period. For example, if you don't add back stock based compensation you're understating cash flow in that period. Would it be prudent to add it bacck in the FCF formula? B) When looking at cash interest and cash taxes in relation to the increase in NWC, how do you account for change in interest payable and taxes payable? That is, using interest as an example, cash interest should detail the cash actually paid for interest in that period but wouldn't that already factor in any interest that isn't paid exactly by the end of the quarter? If interest is expensed, but not paid, you'd write up an interest payable, but by taking cash interest and the increase in interest payable, wouldn't you be double counting not paying the interest and overstating cash flow? C) I was told to only look at changes in A/R, Inventory, and A/P for increases in NWC, so I was wondering if anyone else solely looked at those 3 items and ignored deferred revenues, accruals, payables, and other working capital items> The rationale I was given was because of point B) and to not double count, but these items could often make large swings in cash flow. I can understand looking at only those three when making projections because it could be difficult to project changes in other accruals and payables, but why would you exclude for historical years? Is it possible the logic is that it would make historical years more apples to apples with projections?

Again, thanks for the consideration and hopefully this could provide guidance not only to me, but to other junior employees who are new to corporates.